Internal Exception: io.netty.handler.timeout.ReadTimeoutException

Hoping for this to get fixed, can't join my server 75% of the time.

Here's a screenshot: http://i.imgur.com/govKEcU.png

Edit: Seems to only happen on the recent snapshots, and when googling, it apparently also happened with a few modpacks.
This is ruining my snapshot server because nobody can log on, please fix!

Works now all the time. Thanks Grum! 🙂

Yeah this bug is quite a pain. My only fix is to restart the game or to spam login till it works. Neither of these things are good fixes.

Same here. haven't been able to connect to any 13w41b servers since i started getting this error sometime last night.
I haven't even been able to fix (at all) by restarting minecraft since about 7:40 pm last night either.
EDIT: finally managed to get on, but I'm still getting kicked occasionally!

I am getting this a lot too since updating to this snapshot.

I get this error, Internal Exception: io.netty,handler.timeout.ReadTimeoutException, 99.9% of the time. I cannot connect to 13w41b servers. 1.6.4 and lower snapshots WORK JUST FINE. The server list says 'no connection' for most online servers, and says pinging. If I do get on a server, then log off, I will appear online still (when hovering over number of players), INDEFINITELY. This error seems worse at busy times of the day (or with many servers on the list?), the connection is quite delicate now.

Edit: I am now receiving this error:
Internal Exception: io.netty.handler.codec.DecoderException: java.io.IOException: Bad packet id 64

I am still currently getting this error, just after the server restarted, haven't been able to get on since.

I'm also having this issue, was able to log in once after 5 attempts, got booted after a couple hours, could not reconnect after 2 tries, gave up. Very frustrating, especially as I'm closer to the physical location of the server than anyone else on it but am the only one having trouble (it's a private server, three people total).

I'm getting this connecting to my own server, which is plugged into the same network switch as my desktop box.

I get it on both the 13w41a and 13w41b snapshots.

Same here. Why is it listed as resolved?

because they thought it looked like MC-34646, even though they are two separate issues...
just because they are both netty errors doesn't make them duplicates of each other...
one was fixed, and this was deemed a dupe, and then wasn't fixed...

I am having this issue, on 13w42b. I have not found any fix or explanation for this. All of my servers rarely get past the "Pinging.." part of the status check. And when they do, even with snapshot 13w42b servers, I get this error. I found if you keep trying, you can eventually connect.

This is confirmed for snapshot 13w42b.

One other thing not mentioned here. It will get stuck on the Logging in..... and if you are lucky, you will get past that into the server. It usually throws the ReadTimeoutException, and sometimes it will sit on Logging in.... forever.

I found that if stuck logging in, cancel, go to the main menu, and come back in helps.

Nothing fixes it except maybe a full client reboot, but even then it's not a guaranteed fix.

I have found that as of 13w42b I haven't been able to connect AT ALL in the past 48 Hours, except for a brief 5 minute period (before it kicked me) about 40 hours ago. (I think I was on 13w42a then...)

Yes 13w42b is a lot worse than 14w42a or 14w41a/b. I have resorted to playing on 1.6.4 servers instead of snapshot servers.. Oh well, maybe they will fix it in the pre-release.

finally re-opened. issue never fully went away for me and everyone else on my server. we resorted to going back to 39A with the constant rain, atleast we were able to connect.

Updated to 42b thinking they must have resolved it and its back.... playing fine one min, disconnected with netty error and unable to re-connect the next.

"EDIT: As seen on this post, it generally happens for people with worse connections, though I never got this error in previous versions."

No, this is not correct. I'm running my server at home, and my PC I play the client is connected via 100Mbs Ethernet, not over the Internet. And I get this error often.

""EDIT: As seen on this post, it generally happens for people with worse connections, though I never got this error in previous versions."
No, this is not correct. I'm running my server at home, and my PC I play the client is connected via 100Mbs Ethernet, not over the Internet. And I get this error often."

Yes I have confirmed that even when connected through just an Ethernet wire, the issue still happens.

Anyway, even when I'm playing on my 10Mb\s Wireless Connection, (which has never had any trouble with any servers.) this issue is just as bad as when connected directly via Ethernet.

Problem still persists on snapshot 13w43a. I hope they fix this before 1.7 is released.

Yep, having the issue in 13w43a too. It always happens if I try to reconnect to a server I just disconnected from. I have to restart Minecraft to be able to reconnect again.

I can consistently produce this error by successfully logging into the server, clicking disconnect, and attempting to reconnect to the same server. The screen pauses at "Logging in..." and then gives this error when the login times out.

Same here,

Sometimes even rebooting the client doesn't solve. Something is not syncing with the server, I can read in the console that the client is not seen as disconnected even if it has.
Lots of loading error/lag also even with a lan server, need to force update (F3+A) once every 5 minutes or so.

This is still not working in the 1.7 pre-release.

I'm getting the same error in the 1.7 Pre-Release. I haven't been able to play any of the last few snapshots in multiplayer because of this problem. I get in, I can play for a couple minutes, then get kicked. Come back in, and I need to figure out where I am since I'm not where I was when I got kicked. By the time I figure out where I am and where I need to go, I get kicked again.

You keep marking it "Resolved", but the problem is not fixed. Can you please fix this problem so it doesn't keep happening?

This wasn't fixed...
Still not working in the 1.7 pre-release...
i would venture to say its better, but its still not fixed...
(I'm still getting kicked occasionally and can't join after a disconnect)

I tested this on my Creative server and i got this error 1 out 10 simultaneous connections which is a very very massive improvement

Yes. Confirmed for me in the 1.7 pre-release. This is NOT fixed. Maybe they are fixing it for good in the Official 1.7 release. If not, then I probably wont be playing Minecraft for a while, considering all I play now is multiplayer.

Why is this marked as resolved? It most certainly is not, I'm experiencing this problem right now, unable to join whatsoever.

Been having this through all of the snapshots and still in the pre-release. I play on a server and when traveling in or out of portals it happens about half the time, and also travel by minecart. On the server list it says I'm online until the server is reset and I cannot join the server until it is reset, I continue to get the same error each time i try to join. Unless i stay in one spot, it is pretty much unplayable.

well it was reopened. maybe they can find a fix this time.

Same issue here but it only happens if I log out of a server and try to log back in. If I restart the client, I can get in without issue.
This is happening on a remotely hosted server as well as on a server I run on the same machine.

Sometimes, when i try to connect/ping, my internet hangs up for some strange reason for around 30 seconds. This also seems to sometimes give this error to my client log:

Client> java.net.ConnectException: Connection timed out: no further information: IP/IP:25565
Client> 	at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) ~[?:1.7.0_45]
Client> 	at sun.nio.ch.SocketChannelImpl.finishConnect(Unknown Source) ~[?:1.7.0_45]
Client> 	at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:191) ~[netty-all-4.0.10.Final.jar:?]
Client> 	at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:228) ~[netty-all-4.0.10.Final.jar:?]
Client> 	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:497) ~[netty-all-4.0.10.Final.jar:?]
Client> 	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:447) ~[netty-all-4.0.10.Final.jar:?]
Client> 	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:341) ~[netty-all-4.0.10.Final.jar:?]
Client> 	at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101) ~[netty-all-4.0.10.Final.jar:?]
Client> 	at java.lang.Thread.run(Unknown Source) ~[?:1.7.0_45]

i am still getting this error in 1.7.1. this is by no means resolved

Thanks for reopening this one. It's been affecting our player base for all the snappies/pre-releases since the Netty libs were added.

I'm no expert but feels like a client side issue to me.

My client setup is as follows:

• Java: Oracle JRE 1.7.0_45

• OS: Win7 64bit Ultimate SP1

On the server side: our hosting was very recently migrated, and we had the same issue when trying to connect to both machines

• old hosting Windows Web Server 2008 R2 64bit + Oracle JRE 1.7.0_04 64bit

• new hosting Centos 6.4 64bit + OpenJDK 1.7.0_25 64bit.

Good luck with the fix, I'll be standing by to help test it 🙂

I can confirm I am getting this issue as well.

i have to agree with Shaun above that the bug is client side. i am the only one on my server getting this error.

If it means anything, i have 64 bit java (its the only install on my system) JRE 1.7.0_40 and Windows 8 64-bit.

If i reload my gameclient completely i connect 1st time no worries, if i quit or get booted out of the game, then i get this error when i try reconnecting, but not everyone is getting it apparently, but im also on a 64 bit win7 system.

Normally when logging in, the client sends a "handshake" packet to switch to protocol mode 2, then sends a "login start" packet with the player's username. When this bug occurs, the first packet on the wire is the "login start" packet, which upsets the server as it's expecting a handshake.

I've been able to reproduce this on a local server by logging on/off repeatedly. In 20 attempts, 9 succeeded and 11 hung on "logging in...". Successes/failures seemed to come in "runs", e.g. 3 or 4 consecutive attempts would be successful, then I'd get 3 or 4 failures in a row.

A second nasty race-condition when we tried to send the packet while the connection hadn't been actually established. Fixed now 🙂

Thanks Grum! =)

I believe it will be a ninja edit, i.e. it'll work in 1.7.1 final, which will differ very slightly from 1.7.1 pre.

Confirmed working in 1.7.2!! Awesome. Many thanks!

Actually, I have to disagree. I was able to log into servers with no issue during 1.7.0 and 1.7.1

Now that 1.7.2 is out, I am getting this internal exception issue.

This issue is not resolved. Same exact circumstances, I travel through the nether to get to my base, I enter the portal.. I get a new message that says "Internal Server Error". I wait, close MC and reopen, try to connect and I get the same io.netty.handler.timeout.ReadTimeoutException I've been getting for a week or two now. Updated to 1.7.2 this morning and was pleased as punch to be able to play MC again after a week or two with this mess, and it happens again.

I'm not sure what information would be helpful or pertinent but I'm more than willing to post anything you want to help get this issue actually resolved.

Minecraft authentication servers have been having issues this morning. http://xpaw.ru/mcstatus/

1.7.1, i could not join a server if i left and tried to join it again (unless i restarted).

In 1.7.2, instead of being unable to join a server, i now get kicked out more often while playing (io.netty.handler.timeout.ReadTimeoutException). So i would say its not fixed.

Same Error here, io.netty.handler.timeout.ReadTimeoutException, except I cannot log on. ever. neither can anyone else. on 1.7.2 it need not be mentioned. Definitely not fixed...

Edit: I have one person who can log on to the server, another who can not... the server says:

[INFO] [name] joined the game //<-- he can log on
 [SEVERE] Reached end of stream for /127.0.0.1
 [INFO] /127.0.0.1:50275 lost connection
 [INFO] /--- .255.197.205:51876 lost connection //<-- he gets booted for whatever reason
 [INFO] /---.255.197.205:51933 lost connection
 [INFO] /---.255.197.205:51991 lost connection
 [INFO] /---.255.197.205:51992 lost connection
 [INFO] /---.255.197.205:51993 lost connection

I still get the same error without being able to log on. constantly.

On my hosted server, this has been a serious issue. It started off slowly, with a player or two being kicked and having to log back in with this error. After maybe an hour, it'll ramp up after a reboot. I'll be kicked within 10 min and unable to get back in without a reboot. This issue persists on two different server hosts. Not that this part helps, but it's making server owners look bad as players can't join them.

Any word on this? I'm a bit nervous this is still marked as fixed. If I don't move from an area or go through any portals I seem to be ok, but it happens every time I start traveling again

To the Issues regarding Read Timeouts of multiple Clients on 1.7.2 servers:

We were able to fix this issue by using
-XX:+UseG1GC
instead of
-XX:MaxGCPauseMillis=200

Seems like with standard configuration the garbage-collector was taking 2seconds or more at a time to free space, causing Clients to time out of course. Hope this helps 🙂

With regards to the above comment, the server should use -XX:+UseG1GC and not -XX:MaxGCPauseMillis=200. That was what fixed our situation.

So in regards to the bug: hosted on a different machine (laptop), first time login works fine, next day same problem, utterly unable to connect. ever.
@Marcel: would you be able to post a very brief walk through of how to fix the issue for me ? That's be amazing 🙂

What is boils down to is it appears that Java's default garbage collector causes too much of a delay on the server for most clients, or at least in my situation. Setting -XX+UseG1GC as a Java option helps avoid this situation. E.g.:

java -XX:+UseG1GC -jar minecraft_server.jar nogui

In addition to this option, I attempted to tune it further by adding the -XX:MaxGCPauseMillis=200 option. Supposedly, 200 is the default and I was going to tweak it later. After adding this extra option, the clients started getting ReadTimeoutException. So I removed both options. They continued to get the exception. So I didn't realize until later, in my configuration, I needed G1GC but not the second pause directive.

After enabling only G1GC, everything was much smoother for the clients.

Keep in mind, over time G1GC will experience heap performance issues. On a busy server, it may require periodic restarts. But the G1GC garbage collector can help avoid the "stop the world" situations that netty clients appear to be sensitive to.

Hello, I only bought minecraft a couple of days ago. After the update (1.7.2) i cant join ANY multiplayer servers, this message shows up : " Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host" and sometimes another message that ends in bad packet 5 or 64.Does anyone know how to fix this? ( I dont really know a lot about PCs)

Thanks

@Matthew: Minecraft 1.7.2 cannot connect to 1.6.x servers.

As a complete neophyte I have no idea what you are saying by the G1GC thing, though you say it in such a way as it should be obvious so I apologize for my ignorance, but where do I look to change that setting as you said?

Hi Ok this is my problem, can't connect to any server except mine. Well i can log in but nothing moves i cant interact and 20 - 30 secs later i get the error Internal Exception: io.netty.handler.timeout.ReadTimeoutException. 2 days ago i could connect easily but recently i cant connect at all, i've reinstalled Java, Minecraft and restarted my PC.

Running Windows 7 x64
Used both Java x86 and x64
Minecraft 1.7.2

PS all the servers i try to connect are on 1.7.2 and i've already gotten once or twice the error " Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host" but thats not really an issue.

This is driving me crazy cus i can't connect at all on MC..

I'm getting this. Version 1.7.2 on Linux using OpenJDK 1.7.0_40. I'll join a server, it will load the starting chunk but nothing more and after 30 seconds will disconnect me. "Internal Exception: io.netty.handler.timeout.ReadTimeoutException.

Hi everyone. I'm a noob and I've been trying to set up a MC server for myself and my son. I'm in a different state right now, and it's a great way for us to stay connected and play together. I put together a server using the MC server tutorial wiki and several youtube vids (I can provide links). I downloaded the server files13w36b (exe and java versions), set up my port forwarding, set up the java path in advanced system settings (running 64bit), created my .bat file that works (cmd window pops up and I get no errors, and the server loads perfectly). Then when I open MC and direct connect to localhost (or use an IP) I get the "Internal Exception: io.netty.handler.timeout.ReadTimeoutException" message (it can't connect to my server).

Minor update:
When I try to connect to "localhost" via MC, the Java minecraft server recognizes it and relays the message in the loga and chat screen (x2 examples as I tried to connect twice):
[ INFO ] /127.0.0.1:49500 lost connection
[ INFO ] /127.0.0.1:49605 lost connection

I decided to include the IP addresses. Someone mentioned they are "vanilla" addys, although I have no idea what that means.

Here's an image of Minecraft actually recognizing my server, but not connecting to it http://tinyurl.com/k8j39w9

I'm running this on my laptop:
Windows 8 Pro
Processor: intel Core i7-3667U CPU @ 2.00GHz 2.00GHz
Ram: 4GB
System Type: 64 bit OS x64 based processor

I'm running MC 1.7.2 Paid account.

It looks like some of you have found solutions? What am I doing wrong?

Thanks for the help, sorry if I'm just rehasing some obvious stuff here.

I haven't personally gotten this error yet in 1.7, but I figured I'd update the post as I saw you guys were.

This is not fixed. I opened minecraft 1.7.2, tried to log on to an online server I was on last night, it said 'Logging in..." for longer than usual, then concluded with this error. I just tried again, same thing happened. Since netty has been implemented, multiplayer is 'wonky.' The servers page is all over the place, appearing different each time I refresh it. I wish they would revert because I never had trouble getting onto servers before.

This is absolutly NOT fixed, i can't connect 95% of the time. I had the error on 1.6.4, and still on 1.7.2

My connection works fine.

Under Windows 7 with java 7 update 45 (i already had the error with java 6)

Still NOT fixed on 1.7.2

We have the same problem on our server when ever someone goes into the new 1.7.2 biomes, but as soon as we teleport them back into the old biomes everything runs smoothly.

The players that play on my server also have this issue. They can connect but they will lose connection/disconnect and the error is Internal Exception: io.netty.handler.timeout.ReadTimeoutException we are also running 1.7.2

Ran into this when I DC'ed from a server running 1.7.2 it also lists my username as still being logged in on the server over an hour later.

This is not fixed at all. Everyone on my server disconnecting with this every few minutes. We are on 1.7.2 vanilla. It's the worst when you are exploring new biomes.

Soooo it is cool that Mojang has Minecon and stuff but seriously? All the people asking about this issue since before 1.7.2 came out and still nothing? Every time I enter a portal I get DC'd with this error, my user name is on the server still, and when I come back I've been teleported somewhere else. Once I dropped so far I was down to 2 hearts even with feather fall 4, just appeared in the sky after being DC'd with this error and going through a nether portal.

Problem is not resolved. This has been happening on a server I run since we moved to the 1.7 snapshots and now with 1.7.2. This is not an issue with the network or internet connections. This server had no problem like this prior to 1.7, so it has to be something with the implementation of the new network protocol.

Since this issue is closed, are they even seeing additional comments or should we all report this bug over and over to bring attention to it?

Although it seems like the problem is compounded by minute network conditions, could it be related to the new /setidletimeout functionality, even when it is set to zero?

The reason I suspect this is because a) every player is disconnected at the same moment, perhaps the same tick and b) they do not disconnect with an error flag detected on the server, i.e., they disconnect "gracefully" as if the player logged out (though the player sees an error).

To further explain what I mean, if the player is disconnected "ungracefully," the server usually reports "disconnect.genericReason." But with this situation, instead the server reports "Disconnected" exactly the same way it would report a player just logging out.

So it seems like perhaps the server is erroneously instructing the clients to disconnect. Maybe the server is trying to evaluate if the players are idle, getting into a false positive situation.

By the way, at its worse, I've observed it disconnect every player almost exactly one minute apart for several minutes. It seems too regular, so I suspect something like the idle timeout going haywire, even when it's set to zero. Maybe part of its preparation phase is still invoking no matter what it's set to.

Anthony Martin: In my case I seem to stay logged on even after I got the error message, I even got killed by something while I was offline :/ and on that particular server I get a window when I try to join that has two buttons "respawn" and "Title Screen" but none of them work.
Is this going to get fixed? I still can't play with any profile on multiplayer servers! I'm even getting messages about being taken off the whitelists due to inactivity! :C

Anthony I have seen similar behavior. O my server it seems it does kick everyone at the same time with the io.netty error and on the server logs it does look like a normal disconnect like you said.

I also tried the garbage collector flag like mentioned above and it seems to help a little bit but we still get kicked pretty regularly.

Issue not resolved. My game freaks out if there are more than 7 people on a server and kicks me out with this error. Any attempts to reconnect give the error.

Hello, I am running 1.7.2 and this error has happened to me. It worked fine this morning. The servers are showing that they are running 1.6.4, when I know they are running 1.7.2, and if I try to join using 1.6.4, it works.

Nunya - You can not join a 1.6.4 server with 1.7.2 and visa versa. If you are able to join them using 1.6.4 then they are not on 1.7.2. If I try to connect to my 1.7.2 server with 1.6.4, the Join button is not even available.

Anthony, I changed the value of player-idle-timeout from 0 to 30 and it seems to have solved the problem with the ReadTimeoutException. I am not sure that this workaround would work for everybody nevertheless I play on the server for much longer now without being disconnected.

Sorry I posted that twice. Anyway, I did the opposite, went from 30 (when I had the issue) back to 0 and it also seemed to help, then it happened again 24 hours later. So I think it might be a coincidence. I think network conditions are the major contributor, and netty timeouts are just more sensitive to network conditions than before.

I believe that I am experiencing the same error. I'm running minecraft server 1.7.2 on a world that was created in 1.6.4. I had no problems for the first day of using the world with 1.7.4, then started experiencing the Internal Exception: io.netty.handler.timeout.ReadTimeoutException when trying to connect with the client.
When view the server log I see thousands of errors like the following:

[14:18:01] [Server thread/ERROR]: Wrong location! vw['item.tile.stonebrick'/9942, l='world', x=274.87, y=67.03, z=132.13]
java.lang.Exception: Stack trace
        at java.lang.Thread.dumpStack(Thread.java:1344)
        at aoj.a(SourceFile:572)
        at afn.a(SourceFile:1392)
        at mj.a(SourceFile:480)
        at afn.g(SourceFile:1346)
        at afn.h(SourceFile:1253)
        at mj.h(SourceFile:365)
        at net.minecraft.server.MinecraftServer.u(SourceFile:511)
        at lj.u(SourceFile:265)
        at net.minecraft.server.MinecraftServer.t(SourceFile:441)
        at net.minecraft.server.MinecraftServer.run(SourceFile:358)
        at ky.run(SourceFile:617)

My client gives up, then I see at the end of the log:

[14:18:01] [Server thread/INFO]: accordiondude lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=nul
l, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}
[14:18:01] [Server thread/INFO]: accordiondude left the game
[14:18:04] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 48890ms behind, skipping 977 tick(s)

I suspect that the errors are tying up the server and preventing from responding to the connection request.

Server and client are running on a Windows 7 Pro 64 bit, Intel i7-2620M @ 2.7Ghz, 8G RAM

"Wrong Location" normally shows that there is a corrupted chunk (as far as I know)

This is NOT resolved. I am having a similar issue with the same error message. I can login to the server fine but I keep getting booted every 2-3 minutes with "Internal Exception: io.netty.handler.timeout.ReadTimeoutException"

after 10 min so lagg it very much and then it come up. connection lost: internal exception: io.netty.handler.timeout.readtimeoutexception . Help Me Please Can You Guys Fix It?

A lot of the times if you get this message its mainly due to you having a bad/slow internet connection or a very poor connection to the server itself. I run 2 servers on 1.7.2 and only ever had this issue when using my partners internet once its been shaped, otherwise i can log in an out as many times as i like an have no issues.

I'm still getting this error when I connect to my server. It's not a bad/slow Internet connection. I'm using the internal IP address of the server to connect over a 100Mbs Ethernet connection. Everything worked fine until 13w41a, and it has not worked since.

This issue really needs to be fixed as numerous players are reporting this. As a server owner, this is very frustrating as players are reporting lag that reboots only resolve temporarily. Today has been really bad as players are being kicked every few minutes, even after reboots. They receive the netty error.

In the console, it shows as this:

02.11 18:08:44 [Disconnect] User astolenlife has disconnected, reason: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}

Please fix this issue as it's effecting a lot of servers.

JT I get that same error but I have to look at the save log to see anything, since the console shows nothing. But yes the error and description of what is happening to you is exactly the same has what is happening to me.

This has not been resolved.

I host my singleplayer world through LAN for my roommate to join. Since slightly before 1.7 my roommate began getting kicked for no apparent reason roughly every 15 minutes. Once 1.7 hit, he began receiving the io.netty.handler.timeout.ReadExceptionTimeout error when he got dropped, and drops increased to roughly once every five minutes or so.

This holds true as long as he doesn't wander very far from me. If he does, he drops almost the moment he enters the world.

Nothing of any significance has been done to my network over the last year, so I would be hesitant to believe this is my network's problem in the first place. Add to this the fact that dozens of other people all started getting this at roughly the same time, and this has to be a coding bug. I do not understand why this has been marked as resolved without explanation twice.

It has nothing to do with connections. Everyone on my server dces simultaneously and we are all on different networks with different speeds.

Oh, so this error occurs due to a mismatch of version between the server and client? It was strange, because I did log on to the same server with 1.7.2, but later that day could not. The server must have reverted back to 1.6.4 without me knowing it.

However, when I did log onto the server successfully with 1.6.4, I DEFINITELY DID see the new particle effects as the players hit the ground, that WAS introduced in 1.7.2. This was very strange to me indeed.

No, this has nothing to do with server mismatch. This is the server triggering disconnects on the client side when loading/generating new chunks.

No problems with 1.6.2 and 1.6.4, only on 1.7.2. Our error messages also match the ones shown here and not in that defect.

The only two improvements over the various versions since 13w41a I had:
1. The console doesn't show the netty error message (the one with the increasing numbers as described in https://mojang.atlassian.net/browse/MC-34646) anymore, and
2. I don't need to quit the launcher anymore before I can retry to connect. I can retry after I quit and restart the game.

(Unfortunately I didn't keep track of when exactly those improvements happened, sorry. I only remember they came in this order.)

But the issue to get disconnected after 1-3 minutes making server play impossible didn't improve for me at all.

As of today, I am receiving the same error.
Failed to connect to server
Internal Exception: io.netty.handler.timeout.ReadTimeoutException.

This issue remains unresolved. The issue has become localized to 1.7.2 for myself: only one server throws this exception, and this is localized to my home internet connection. Connecting to the same server via MineChat on an iPhone using the same account has been successful, so the issue is not a profile mismatch.

I don't know if this helps for anyone else, but it did for me. I run my own server out of my home, and my router allows me to prioritize computers. I had my server in there to prioritize higher than other computer/devices, and was getting the error. I removed it from the high priority and made it normal priority, and I'm no longer getting kicked out with this error.

Just thought I would pass it along in case it might help anyone else out.

This error is still present in 1.7.2, I've got a Mac computer if that has any relevance, and it only happens on one server, while the rest work fine. I'm not sure why, I have no personal connection to that server unlike the above mentioned reports, and I recorded a video of it I hope its okay if I post it here. https://www.youtube.com/watch?v=22G_g9weabo

I was just able to connect to that server miraculously, no clue how I fixed it I cleared my entire Minecraft folder but after doing that it still gave me that error… Not entirely sure how but I was able to connect just now.

We seem to be having this problem on our server almost daily. Please, fix it!

Confirmed in 1.7.2 it is still occuring. Actually had this happen on our server last night. It seems to happen due to a corrupted scoreboard.dat, removed the file and the server worked fine, replaced from previous day backup and it was fine. Attempted to recreate the issue and was a no-go, but I did capture the corrupted scoreboard.dat... attached.

This corrupted scoreboard seems to cause the io.netty issue, and will kick all players from the server when it happens. Attempting to reconnect failed until the corrupted scoreboard.dat was removed/replaced.

That looks fixable without a needed update. Weird how that happens when people explore and not when they are in already explored chunks. Can we just remove the corrupt file or do we have to replace it with a clean one?

We have been having this problem forever now and we dont use a scoreboard. I dont have access to the files but I know we dont have one nor has the command ever been used.

It's possible other .dat files are corrupting causing the same issue, however I cannot confirm this. Maybe someone else who is having the issue but not using the scoreboard can test this.

Well, things seem to be moving. I will try to isolate a corrupt dat to help a little. In any case, thank you to finally re-open this ticket !

We do not use the scoreboard on our server. How are you determining a .dat is corrupt? What are you replacing it with or will the game generate a new one if missing?

For me this bug is localized to a certain part of the map. If players go near that part of the map the cpu usage goes up to 100% then everyone disconnects with that message. Once no ones in that area the server stops lagging and everything returns to normal. Is this the same bug or should I open a new bug report?

It's starting to look more and more like a generic error caused by multiple different things. I think the main one is people exploring new chunks kicks everyone on the server. We've also seen the above corrupted scoreboard issue for those with a scoreboard and now your issue with one bad chunk.

@Kyle Harris - Neither, sounds like you either have a corrupted chunk, corrupted hopper-timer/redstone, or something specific causing an issue on your server. I would check the area that lags the server for the source.

@Joseph Meyers - The server will create a new one if it's missing. I personally tested with removing it AND restoring the previous day's scoreboard from my server backups.

@Talven81 - we don't use the scoreboard and I can't find the dat file for it anywhere. I did a quick look through the other dats but all of them should be the normal ones required for basic play; map, level, uid, mineshaft, stronghold, etc...

@Joseph Meyers - You will not have one unless you use the scoreboard. As far as the other .dat files, it's possible to have one corrupted even if they are for "normal play". Back up your server first, then remove a .dat and try to connect to see if it resolves the issue. If one is corrupting it's possible that others are.

We don't have a scoreboard either, but I just tried deleting all the other .dat files in the data folder and we're still getting kicked with the error. Seems like nothing fixes it. It's really driving us all crazy not being able to stay in the server for more than 2 minutes at a time.

Interesting... removing the scoreboard.dat definitely fixed the issue we experienced. @Joseph Meyers might be right, "a generic error caused by multiple different things".

I deleted the scoreboard.dat file, but it still kicked me out of the server with the same message. Maybey it is helpfull to say that not everybody on our server suffers from this problem? Another player didn't got thrown when i did got thrown out of the server..

Yeah I've noticed some people are way more prone to getting kicked than others are, but I know for sure each and every one of us on my server has been kicked numerous times. Sometimes it's a bunch of us at the same time, while a few people are okay. Other times it's like one person over and over.

Guys, it's a save spike. I've all but verified this. If you switch off auto-save (/save-off) then periodically use /save-all (cron job every 15 minutes (with a script that does /save-on, sleep, /save-all, sleep, /save-off)), then disconnects only happen then, and not every time. If my case, I've seen /save-all take as long as 60 seconds, which is plenty of time for the client to time out.

It's NOT safe to use /save-off. Just do it for troubleshooting ONLY. You will lose data if you use /save-off without periodically using /save-all. You will lose data if you stop your server without first doing /save-all. And I've been informed that /save-all doesn't work unless you first use /save-on in a different tick. If you wait too long to use /save-all, you will get an out of memory exception and lose data. *So use with caution.*

Also, see: https://mojang.atlassian.net/browse/MC-33086

@Anthony Martin - It definitely could be related to saves as well, which would relate to my corrupted file comments above. However I'm starting to agree with the other posters that there is not one specific condition that is causing it. While the saving could instigate delaying the server and causing the disconnects, placing a corrupted .dat in the server also causes the issue however is not correctable by stopping saves, restarting the server, or anything but removing the corrupted file.

To all, if you are identifying various issues related to this please do continue to let us know what circumstances can cause this error and what helps resolve it. It might give the devs a clue to its source.

My issue is it kicks everyone when exploring. If everyone stays in already generated chunks we can play for days no problem. As soon as anyone starts going into unexplored chunks everyone gets kicked every minute or so. This is not an exaggeration. It is every 1-2 minutes the server gets kicked. Once those previously new chunk have generated and people have been there for a while the server is again back to normal.

Forgot to mention this, but it isn't an exploring thing on our server. Happens at really random moments.

If corrupted .dat files are related to the timeouts, I see the following message on occasion at startup on the console (not logged):

s: Loading NBT data
        at dg.a(SourceFile:335)
        at dg.a(SourceFile:37)
        at dg.a(SourceFile:329)
        at dg.a(SourceFile:37)
        at dr.a(SourceFile:107)
        at dr.a(SourceFile:78)
        at dr.a(SourceFile:14)
        at ayc.a(SourceFile:45)
        at afn.a(SourceFile:2484)
        at atp.a(SourceFile:241)
        at atp.a(SourceFile:26)
        at apj.a(SourceFile:30)
        at aph.e(SourceFile:448)
        at mi.f(SourceFile:123)
        at mi.c(SourceFile:72)
        at mi.d(SourceFile:108)
        at afn.e(SourceFile:311)
        at afn.a(SourceFile:249)
        at ul.f(SourceFile:275)
        at ul.m(SourceFile:261)
        at ul.a(SourceFile:61)
        at uo.a(SourceFile:48)
        at mj.b(SourceFile:143)
        at net.minecraft.server.MinecraftServer.u(SourceFile:503)
        at lj.u(SourceFile:265)
        at net.minecraft.server.MinecraftServer.t(SourceFile:441)
        at net.minecraft.server.MinecraftServer.run(SourceFile:358)
        at ky.run(SourceFile:617)
Caused by: java.io.EOFException
        at java.io.DataInputStream.readByte(DataInputStream.java:267)
        at dg.a(SourceFile:318)
        at dg.a(SourceFile:35)
        at dg.a(SourceFile:329)
        ... 27 more

As mentioned earlier with the .dat files, I can confirm that deleting the data folder on my server and rebooting has so far resolved the errors. I backed up the folder and deleted it. Haven't had any of the players on my server report any issues for over 24 hrs.

The fact that the .dat files are being corrupted as I had to setup a new map when 1.7.2 was released publicly, and the server didn't have the netty errors for quite a while. It had been experiencing them with the previous map.

Update: The netty error has returned. Apparently deleting the corrupt files only does a certain amount of good since the world will just corrupt it self again. We need some fixes to come out soon.

Can report the same bug. Edited my map with McEdit. 2 of my friends can join but when a third one joins i get this error. I tried everything, deleting the datfiles but nothing works

I think restarting has more of a benefit than deleting dat files. Since you have to restart to properly delete dat files, it seems like you're doing something beneficial for performance, but in reality, the restart was the thing that actually helped, in the short term. Long running servers have more Full GC cycles and restarting eliminates that for a while. Full GCs contribute to the problem. The more Full GCs there are, the more pauses. Long pauses cause clients to time out. Full GC combined with periodic, random save spikes can cause random disconnects.

The root cause is not specifically saves. The root cause is not Full GCs. Combine the two, however, and can you have pauses greater than 20 seconds, on occasion, which is too long for the clients.

See: https://mojang.atlassian.net/browse/MC-33086

@Anthony Martin - You are incorrect about the .dat issue, you should do some testing first before saying it's not the issue. Several mods have tested this and the .dat file presented the same issue after restart until it was removed and was definitely a root cause (there may be several root causes for this issue), restoring from a backup worked fine, as well I was able to replace the corrupted scoreboard and recreate the issue. Also I am running +DisableExplicitGC. However you do have a point of the delay with GC and saves.

I understand, but note, I didn't say deleting .dat files was excluded from being a solution, I just recognize that restarts are involved, and restarts often help without deletion. I don't have to personally test it to see that some servers do not report benefit from deleting .dat files.

I may be incorrect about the .dat contribution to the problem, or lack thereof, but I'm basing my assumption on the fact that some people have reported that it made no difference. I have verified that restarts often do make a difference, sometimes multiple restarts in succession. Is it beneficial because those particular .dat files don't get loaded after restarts because the player decides they've had enough and do not to reconnect for a while? Perhaps.

But just deleting data is not currently something I'm willing to troubleshoot on my 25 GB server with 16 MB of .dat files from 2600+ players. It would be too much of a disruption and a huge amount of confusion for the players. If I just deleted it all and restored it later, players won't put the server through its paces. They'll stay off the server until the files are all restored from backup. So there's little point.

At the moment, players on my server are only interrupted at most, 4 times an hour from disconnect waves because I concentrate all the saves to once every 15 minutes. Sometimes we go hours without disconnects. Sometimes it's every 15 minutes. But at least it's not completely random or once-per-minute anymore.

I will say this, supporting the idea .dat files have problems: last week, three users found themselves at spawn after an early morning automated restart. It makes me wonder if their .dat files were in fact so corrupt, they couldn't be saved at all. I reviewed the logs, and there were no exceptions or errors of any kind. There was also no indication that there were greater or fewer disconnect waves prior to this or after. In other words, it didn't seem to matter. Maybe that's because there are hundreds of users with these corrupt files, and that three got deleted didn't make any difference.

I'm experiencing something different. Any server I join will instantly stop loading chunks so that there's only the few I spawn near, then after 30 seconds I disconnect with the error message. During my "connected" time I can break blocks but they don't drop anything, can't see people etc.

Also, I'm at University using their internet so I'm worried that might be affecting it somehow.

I friend fixed it for me! When you're logging in you've got to tp your self in to another chunck. You can do that with the control pannel of your server. If it isn't your server you neet to contact with the server owner.

This is related. In my case, save spikes are indeed caused by minecraft.dat. Client timeouts can occur if a) the server is already behind (Can't keep up!) and b) the save takes long enough. The combination can cause the client to think the server is no longer responding. It is my understanding that the timeout threshold is 20 seconds. So if it takes 10 seconds to do a /save-all (random), and your server is 10 seconds behind (or any combination), you have a high chance of timeouts.

See: https://mojang.atlassian.net/browse/MC-33134

Is there any news from Mojang on getting this fixed? It's a bit frusting that my server is suffering from issues and to see tweets about adding Twitch.

The only way I can resolve this on my server to delete the data folder. This is only a temporary resolution as the server will being to lag and start throwing netty errors again after about 3-4 days.

Recently got this error on my home hosted server for myself and friends. Its stopping anyone from connecting to the server and even a client on the same computer as the server is unable to connect and gets the error.

From the server log:
[22:36:52 INFO]: Rappaport/127.0.0.1:51298 logged in with entity id 322 at (-74.69999998807907, 80.0, 177.4108475771652)
[22:36:52 INFO]: Rappaport joined the game
[22:36:52 ERROR]: Chunk file at -9,13 is in the wrong location; relocating. (Expected -9, 13, got -3, 13)
[22:37:23 ERROR]: Encountered an unexpected exception
java.lang.OutOfMemoryError: Java heap space
[22:37:24 ERROR]: This crash report has been saved to:

Opened the log to see:

Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 11/20/13 10:37 PM
Description: Exception in server tick loop

java.lang.OutOfMemoryError: Java heap space

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– System Details –
Details:
Minecraft Version: 1.7.2
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_45, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 170214032 bytes (162 MB) / 259522560 bytes (247 MB) up to 259522560 bytes (247 MB)
JVM Flags: 0 total;
AABB Pool Size: 4298 (240688 bytes; 0 MB) allocated, 4039 (226184 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
Profiler Position: N/A (disabled)
Vec3 Pool Size: 635 (35560 bytes; 0 MB) allocated, 537 (30072 bytes; 0 MB) used
Player Count: 1 / 10; [mm['Rappaport'/322, l='Grand Start', x=-74.70, y=80.00, z=177.41]]
Is Modded: Unknown (can't tell)
Type: Dedicated Server (map_server.txt)

Anyone experiencing this error on a wireless connection? Because it only happens to me when i'm not a wired one. Thought that was quite interesting. Also this is the same with my 4 computers at home. Also this only happens on servers where scoreboard data is used. (Hypixel, Mineplex etc....)

Yikes, this is happening to me on my home LAN! Only started happening since I set up a vanilla 1.7.2 server. Never saw this on Craftbukkit.

Oh my, has this affected me! I cant connect to any servers OR play singleplayer!?

?

?

?!?
Note: I got single to work now.

@Mars Ice: What is the solution ?

I receive this same message along with a few others when trying to play on my server, but other players are not having any issues. However I am able to log in and play with no issues after 1am gmt.

I am able to log in with no problems, however when I place blocks there is no audio cue and when I break it I get no item. After about 30 seconds I get the error message.
Other occasions, the world doesn't load and I am forever falling into darkness until the error message.

I have only been experiencing these issues in the 1.7.2 version, the server worked beautifully before.

I can reliably reproduce this bug on our server by driving in a minecart for a longer distance.

Watching the debug screen while driving shows a huge amount of chunk updates (up to 640). Also, the longer the distance the lower the fps drop, ultimately lagging (sever block lag and sound lag) for every player on the server before crashing. After a restart, the server works fine again.

On my server, we had been able to avoid getting constantly disconnected by staying inside the newly explored areas and not exploring much more. Today, I have encountered the same error when trying to login. It takes forever to attempt to login and then gives me the io.netty.handler.timeout.ReadTimeoutException error. Now I can't join the server at all. Please, fix this! it is getting extremely frustrating not being able to play the game properly.

Just happened to me. Was just walking and was kicked off. Terminal log was hung. I entered Stop + Return and after a solid 30 seconds I found the following:

[10:45:55] [Server thread/WARN]: Time ran backwards! Did the system time change?
[10:56:08] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 181703ms behind, skipping 3634 tick(s)
[10:56:08] [Server thread/INFO]: george_clooney lost connection: TranslatableComponent{key='disconnect.genericReason', args=[Internal Exception: io.netty.handler.timeout.ReadTimeoutException], siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}
[10:56:08] [Server thread/INFO]: george_clooney left the game
[10:56:10] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2128ms behind, skipping 42 tick(s)
stop
stop[10:56:10] [Server thread/INFO]: Stopping the server
[10:56:10] [Server thread/INFO]: Stopping server
[10:56:10] [Server thread/INFO]: Saving players
[10:56:10] [Server thread/INFO]: Saving worlds
[10:56:10] [Server thread/INFO]: Saving chunks for level 'jjHappyLand'/Overworld
[10:56:10] [Server thread/INFO]: Saving chunks for level 'jjHappyLand'/Nether
[10:56:10] [Server thread/INFO]: Saving chunks for level 'jjHappyLand'/The End
[10:56:11] [Server Shutdown Thread/INFO]: Stopping server
[10:56:11] [Server Shutdown Thread/INFO]: Saving players
2013-12-04 10:56:11,783 ERROR Attempted to append to non-started appender ServerGuiConsole
Exception in thread "Server Shutdown Thread" org.apache.logging.log4j.core.appender.AppenderLoggingException: Attempted to append to non-started appender ServerGuiConsole
	at org.apache.logging.log4j.core.config.AppenderControl.callAppender(AppenderControl.java:89)
	at org.apache.logging.log4j.core.config.LoggerConfig.callAppenders(LoggerConfig.java:425)
	at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:406)
	at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:367)
	at org.apache.logging.log4j.core.Logger.log(Logger.java:110)
	at org.apache.logging.log4j.spi.AbstractLogger.info(AbstractLogger.java:1011)
	at net.minecraft.server.MinecraftServer.n(SourceFile:292)
	at kx.run(SourceFile:605)

Running on a 8GB ram Mac Mini (Core 2 duo). Only 1 player on the server, me, and top reported a minuscule amount of CPU usage... so not sure what's going on. Need anything else? 🙂

Thanks!

Joel

I get this without fail within a few minutes of play. I just recently upgraded from much older world data (1.5.x). I'm finding 1.7.2 completely unplayable. Have I missed something perhaps in upgrading my server? :\

I know you must be working hard to solve this but it is becoming very irritating as i cannot join any serers because of it.

I've received this error while playing a LAN game with a computer in the same room. I'm also receiving this error as well and the client is constantly dropping the connection every couple of minutes.

Internal exception: java.io.IOException: an existing exception was forcibly closed by the remote host

Hello gents,
I woke up this morning to find the following in my server's terminal:

[00:03:33] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6478248ms behind, skipping 129564 tick(s)
[00:42:37] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2293780ms behind, skipping 45875 tick(s)
[02:31:26] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6478053ms behind, skipping 129561 tick(s)
[04:20:14] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6477580ms behind, skipping 129551 tick(s)
[06:09:03] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6478759ms behind, skipping 129575 tick(s)
[07:57:51] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6477748ms behind, skipping 129554 tick(s)
[07:57:53] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2011ms behind, skipping 40 tick(s)
[09:02:31] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 3829528ms behind, skipping 76590 tick(s)

The load was currently hovering at around 35% of 1 core, which seems high for a server to idle at with no one logged in and playing, but at the same time low for me to be seeing Server unavailable in the Multiplayer pane. Seems there is in fact something uncontrollably spiking CPU usage after all, even when the server is empty.

EDIT: Attaching some logs.
EDIT 2: Just kicked off while connecting directly within my own network (10.0.1.5). Same CPU behavior...

Joel Hansen, how big is your data/Mineshaft.dat file?

@Anthony Martin My world folder, imported from previous versions, is 97MB. My region folder is around 80MB. My entire server folder is under 200MB. Want the whole thing? 😛

No, I'm just wondering about your data/Mineshaft.dat file, actually.

@Anthony Martin
Haha. My bad.
So, my /minecraftserver/data/ folder only has one file in it, villages.dat. It's 55 bytes in size.
EDIT: /minecraftserver/world/data/Mineshaft.dat is 19KB.

Joel Hansen, thanks. I was curious because your symptoms seemed similar to mine, but in my case, my Minecraft.dat literally grows by multiple megabytes each day, which results in the "behind" logging messages getting higher and higher.

Then again, the total size of my SMP world is 36GB, so maybe this is perfectly normal. Mojang hasn't said one way or the other.

Another 11 minutes of play:

[15:57:58] [Server thread/INFO]: george_clooney joined the game
[16:09:27] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 25735ms behind, skipping 514 tick(s)
[16:09:30] [Server thread/INFO]: george_clooney lost connection: TranslatableComponent{key='disconnect.genericReason', args=[Internal Exception: io.netty.handler.timeout.ReadTimeoutException], siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}
[16:09:30] [Server thread/INFO]: george_clooney left the game

at first, it would happen maybe once a day, but not i can not even get onto servers at all.

Someone has to start working on this ASAP. A popular issue that cannot be overlooked.

it happens TO ME TOO , HOW DO I FIX THIS ?

For anyone experiencing the problem where the game loads only a few chunks, doesn't allow world-interaction then kicks you with the error after about 30s, you're probably not experiencing this bug.

I had the above situation due to my University internet connection unintentionally breaking Minecraft internet traffic. My University Minecraft Society are using Hamachi and I personally am now using a VPN to bypass the University filtering which works well but costs, not sure if a free VPN would be reliable enough.

To conclude: In the above situation the error message seems to be a legitimate one as opposed to a bug. Using a VPN will fix it.

@Henry, I really doubt anyone could afford a reliable vpn as well as operate it properly in order to fix this. I'm experiencing the "loads only a few chunks, doesn't allow world-interaction then kicks you with the error after about 30s" issue, but with additional details on the note. Either way, we all receive the same message at the end. Do you know any other possible solutions?

@Henry FYI Hamachi is squatting on other people's IP address ranges and using them illegally. Highly unsupported, any issues experienced with Hamachi are invalid, and not considered on this bug tracker.

The 25.0.0.0/8 block is allocated to the British Ministry of Defense. Organisations who need to communicate with the MOD may experience problems when more specific Internet routes attract traffic that was meant for internal hosts, or alternatively find themselves unable to reach the legitimate users of those addresses because those addresses are being used internally,[2] and such "squatting" is against the established practice of the Internet.

@Talvern
Wow, well I wasn't aware of any such thing and apologise for bringing it up.

@Smikis
I don't know of any other solutions for my particular situation, however I do think that the error is being caused by my network and not as a bug, at least not in the same way as most of this thread. Could your internet connection be limited in any way similar to mine?

Hi, I have been having this issue as well. I log into the world for 10-30s and then everybody stops moving and chunks stop loading as well. Also, if I go into a server with a timer (survival games), it will stop. Then about 10s later, io.netty.handler.timeout.ReadTimeoutException will appear and I get kicked.

It may be something to do with my connection, but I need to know what it is in order to troubleshoot it. It's not computer specific, I tried another computer that uses the same network (home) and it comes up with the same symptoms. It also occurs on every server I connect to.

Only happening on one server, all other servers in my list working fine.
"lotr.empirewar.org"

I get Internal Exception: io.netty.handler.timeout.ReadTimeoutException
on softslayer.com and softslayer.com:25565 on MineCraft version 1.7.2

It happens to me on 1.7.4, and I can't get back on a server.

This tends to happen more and more frequently on my hosted server. From time to time everyone online will get this error and be booted off the server for what appears to be no reason at all. We're all using different connections as we're all scattered through out different states of the USA and even countries.

Today has been particularly bad especially and we just don't know what to do about it.
I've been hunting all over the place trying to find a way to make this happen at least a little less with no luck

I'm having the same symptoms as Isaac, however, I'm able to play from around 1:30AM to I'm assuming at least 4AM without the error and the connection being fine. Then during day time, it reappears again.

Hey Smikis,

Do you have a Billion modem? What's your ISP? I have a feeling that its one of these two.(I'm on TPG, Australia)

I have Billion modem. Works ok when using wifi. Get error when same laptop is connected to modem via Ethernet. Club telco is ISP.

Wow, I never thought that using a wifi connection would fix and issue. It's usually the other way around. I'm no longer getting the error with wifi, how does this even work?

By the way, what firmware do you have on your modem, I have 2.22a, which is old because I never bothered with firmware. Do you have an updated version?

I'm having the exact same problem as Smikis Pikis, on an okay connection (6.2MBps right now), on both 1.7 and 1.6 servers. I managed to log on last night at about 1.45am (GMT) to the game working but no such luck any other time.

I get this error message whenever i get disconnected from a server due to lag (not sure if server-side or client-side). Thankfully that doesn't happen often.

i play on a small server (me and around 15 mates). we all get the problem, but we tell the owner who restarts the server, and we can geton for a couple hours. i know this is advice is no good for larger servers, but it may help for people who use smaller servers... 🙂

I have found a reproducible case!

I have a remote player that I ran some tests with, and this error occurs only when viewing a large number of animals. For example, I have the remote player connect, and stare at a blank wall or simple, non-moving scenery. They can stay connected for longer than we felt like waiting, 10-15 minutes at least. Then I had them spin 180 degrees and look out and down from their elevated house at three full pens of animals, and within seconds they are disconnected.

This happens every time, seemingly independent of connection speed. And the animals freeze in place just before the disconnect.

I have seen this happen to me too. I thought nothing of it since I was running Bukkit software and did a /reload. But, I guess there's more to it.

This and major lag has been happening to my server ever since the 1.7.4 release.
However, this never happens when I'm on the Element Animation server. The main difference between the two is that the EA server has plugins and mine doesn't.

EDIT: A very similar problem happened in back when my server had only half a gigabyte of RAM (it now has 1 gigabyte), back in 1.6. Could it be possible that this is only affecting servers with low RAM?

I've been having this problem for about 3 months now. We got a new computer that could log into multiplayer from a different internet connection but we play at home and from here I can't log into any servers.
Is this ever getting fixed? Because basically we can no longer play multiplayer which is all we do.

Boxfigs:

I'm running 32GB memory for my MC server on a box with 64GB memory total, and I still get the error - I don't think it is necessarily related to memory, although a very small amount of RAM might cause it to happen more frequently.

I just got a new error while trying to connect, instead of the one on this thread:
"Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host"

I appear to have the same problem with LAN, albeit with a slightly different message: "io.netty.channel.ConnectTimeoutException: connection timed out”. This problem may appear on servers as well, but I do not play enough on servers to know for sure.

Happens on and off for players on my server... quite annoying.
Gets much worse when player's connection speed/quality drops.

I get this to every time I reload my Bukkit server - Might be a issue from Multiverse (Didn't have it without MV)

A friend of mine was suffering from this bug. I got him to increase his RAM allocation to Minecraft from 1GB to 2, and it seems to be running as normal. No idea if this change directly affected this bug or if it's a coincidence, but worth a shot at least while we await a fix.

I have a Retina Macbook Pro with 16 GB of ram, 8 of which are allocated while Minecraft is running. RAM is most definitely not the problem.

So... How could i fix this problem?

Because in my server it passes with some people. It says this:

31.12 21:54:31 [Disconnect] User [21:54:31 INFO]: KnightAlive45 has disconnected, reason: Internal Exception: net.minecraft.util.io.netty.handler.timeout.ReadTimeoutException

In some other forums there are some people talking about this:

• http://www.spigotmc.org/threads/only-some-users-crashing.9129/

• http://www.minecraftforum.net/topic/2054190-17-pre-release-internal-exception-ionettyhandlertimeoutreadtimeoutexception/

• http://pastebin.com/42JrS7ZW

And if you find in google you will find millions of more posts.

Please Mojang, try to fix it. And please, if Mods or Mojang staff, if you know how to please tell me! Thanks to everyone, and have a Happy New Year!

I am currently having this problem but it is only with one server all the rest are fine.

I found a temporary fix to it, download a ip changer so that it doesnt keep the same ip, the one i use is "hotspot Shield" it enables me to connect it is VERY helpfull 😃

Randomly started getting this issue.. I can't connect to my own server and it's driving me mad. Strangely-- I haven't had this issue with any other server yet, only mine. My server sort of operates around me so it's a little bit important that I get on soon. Help!?

I've tried deleting the 1.7.4 version and redownloading it; it did nothing.

We started getting this error after doing some extensive exploring in new chunks generated by the new terrain gen (our world's been around since 1.6). We had no problems with the new terrain gen for quite a while; it only started after a couple of us went exploring on horseback very far from where we'd been previously (5-10k blocks) When we go back to the chunks generated BEFORE the issue began we don't have problems. Also, it happens less regularly when there are less people on the server, and when the explorer stays in one place in the new chunks generated, not moving around much.

Please fix soon! It's becoming quickly unplayable on our server!

Having High CPU usage and disconnects when exploring new terrain (Vanilla 1.7.4 created map on 1.7.2) Exploring new terrain is impossible now. Standing in the same spot for 15 minutes is not a problem, server load goes down. When i move a few blocks into unexplorered territory: server load goes to 100% and almost always disconnects me.

I have the same issue on my server.
When starting minecraft (1.7.4 vanilla, on a linux debian wheezy 64bits) everything is fine until I log in, then the RAM used starts increasing and increasing (1GB allocated at startup in java command line, 4GB max available on my PC)
Then once it starts swapping (ie > ~3GB used !) it becomes being unresponsive, and finally I get kicked out of the server with

Internal Exception: io.netty.handler.timeout.ReadTimeoutException

The RAM doesn't go down, I have to stop the minecraft server (well, kill it, it doesn't want to shutdown...).

Logs from an example where I got kicked after 30 minutes (I didn't move a lot at all, maybe 4 chunks max for X/Z, since I'm building a tower)

[14:27:47] [Server thread/INFO]: Preparing spawn area: 87%
[14:27:48] [Server thread/INFO]: Done (4.834s)! For help, type "help" or "?"
[14:37:48] [User Authenticator #1/INFO]: UUID of player Soqaris is xxx
[14:37:48] [Server thread/INFO]: Soqaris[xxx] logged in with entity id 498 at (1066.6724007394362, 207.0, -425.10808115528613)
[14:37:48] [Server thread/INFO]: Soqaris joined the game
[15:07:43] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2558ms behind, skipping 51 tick(s)
[15:08:33] [Server thread/INFO]: Soqaris lost connection: TranslatableComponent{key='disconnect.genericReason', args=[Internal Exception: java.io.IOException: Broken pipe], siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}

The high load of my machine is due to the minecraft server (90% of the RAM used, the CPU load is ~50% on a 2-cores CPU so it's not a bottleneck or an issue here)

Hi! I just got this problem. It seemed to have occured exactly when I was exploring the world in creative mode and went over the edge of the world. At that point two other players got the exception. My views got distorted but I did not get the exception. After that we get the exception frequently. Can it be that the data of the world has been corrupted? I don't know, just a guess.

This has happened for me in the 14w02c snapshot. I was invited to a server, and after a few hours of building in the spawn area I went to search the Nether for a fortress, I barely managed to get 100 blocks from the hub when I was kicked from the server with this error. Each and every time I try to connect, I get the same message; what it weird is that according to the multiplayer menu I'm already on that server. Very odd.

This happens very very frequently on my computer. Even on servers hosted on same machine which is the messed up part.

I have a packed computer (Pretty powerful) no bottlenecks on it.

This bug occurs in 1.7.2 and 1.7.4 for me however it might not actually be occuring in 1.7.2 because that could actually be a mod doing it. But in 1.7.4 is pure vanilla sooo. Its still an issue there.

I can't run proper stress tests, but this is almost certainly related to world travel on the server I play on. Every time this bug hits, someone who was logged on reports "I was on a minecart in the nether" or something similar.

I built a nether cart track to a portal to a mesa biome. This is strictly off limits because going to that portal triggers the bug seemingly without fail.

Affects 14w03b.

Occurrences of this error started happening on our small server in snapshot 14w03b. For the first time players started dropping out with this error message when entering the end. Logging in is impossible afterwards, usually they just get this error message before being disconnected. In rare cases the world starts loading for about 1-2 seconds before they are disconnected with the same error message.

From the server selection screen the server still reports dropped players as active on / connected to the server.

Our server has become pretty much unplayable because of this issue.
The past hours have been spent like this:

1) We start the server
2) Everything seems to be oka–OHWAIT
3) A wild io.netty.handler.timeout.ReadTimeoutException appears!
4) Everything stops working, we kill all the processes
5) We try to figure out what's wrong
6) We fail
7) Go to 1)

Please help us Mojang, you're our only hope :/

Some observations:

On our (same one as the one Jemus42 reports for) server, the problem has occurred since 14w03b. However, since today it always happened when a certain player logged in. We managed to solve the problem (at least for now) by editing his playerfile and "teleporting him" from the End to the overworld. He was also in a minecart at the time when him logging in was apparently constantly causing crashes, and I have removed that in his playerfile, too. So this might have something to do with minecarts or The End (it didn't happen for players in the Nether and we have not dared to enter The End again).

same problem here. as soon as i entered the end on our server it keept crashing as soon as i joined the game and gave a io.netty.handler.timeout.ReadTimeoutException.
I had this exception occasionly before but since 14w03b it crashes minecraft as soon as someone is in the end.

Just happened to me today, using a Bukkit server that I created. No matter how many times I try to log in it keeps on saying it.

It is pointless to post Bukkit stuff here as this is not the bukkit bug tracker.

On our server noone did anything with minecarts / rails, the error just started popping up as soon as the first player entered the end. We reverted to our 1.7.4 backup which worked out fine for the night, except that today the same error appeared after staying for about 4-5 minutes at an (admittedly CPU/RAM intensive) ender farm.

I've tried to send a tweet to Grum, and he replied me this:

What is there to fix about it? It's caused by no data on the socket.

https://twitter.com/_grum/statuses/422020974905540608

I'm hoping someone still finds a solution for this bug.

" (...) What is there to fix about it? It's caused by no data on the socket."

So in other words, this is a new bug that is just not going to be fixed?

So in other words, this is a new bug that is just not going to be fixed??

No, the exception is a symptom for a problem that may be with your connection, the server (both minecraft or other software), or the client (both minecraft or other software). If you get this message while being in the End you might want to look for other bugs referring to problems in the End because most people that voted for / reported this "bug" have a problem that is unrelated to yours.

Thanks for your comment, I'll look into what other bugs might affect our server here.

On the other hand, there is some similarity with other user reports based on this 'bug's' occurrence in 14w03b, as this error message seems to be encountered mainly (exclusively?) now when in the end.

In addition, while there are of course a lot of things I might not be aware of and I might be simply overlooking in this case, the only change in our server setup before the error message started popping up was the upgrade to 14w03b.

I forgot to inform that I also tried this on a regular server i made that was downloaded from Minecraft, and the exact same thing happened. I tried today, and both servers are still doing it. No matter how many times you click join. It still says it. I have counted how many times my minecraft server did this by using a counter, and I have tried 739 times. I was up for 6 or 6.5 hours trying to see how to fix my problem, but there is no solution i can think of.

This internal exception seems to happen to me using any new world I create in the snapshot 14w03b, Single player or multiplayer.
I create a new world in creative mode, I find the end portal using eye's of ender. I go to the end. Stay in the end for a while and then the server freezes!
P.S. I start throwing snow balls to see exactly when the server stops responding.

I realize this is not a true fix by any stretch of the imagination, because it requires foregoing a major part of minecraft functionality, but try breaking all redstone clocks. I noticed a few months back that an active clock would cause the game to slow down considerably, but left them running because I didn't mind it. Then we wondered if that drop in performance could be causing out timeout problems, and lo and behold, since interrupting those circuits, we haven't had a disconnect yet.

Ugh so many different issues with the same error muddying up this report. Early on this problem was with exploring new chunks. Now people are reporting stuff in Bukkit, mods, memory, the End and who knows what. Most people on my server have stopped playing since the first update causing this since they can't explore any new chunks. That was the main issue this report was for if I remember correctly.

@Joseph Meyers: Have you looked at issue MC-33134?

Yes, that was spawned as a result of this report. Our server experiences no cpu or ram spikes like that. The dat file removals seem to have no affect either.

Don't know if you guys knew this, but when you use BungeeCord this problem doesn't occur

I hope this problem can get fixed soon its really annoying. ;{

Considering it forced me to set the server version back to 1.7.4 (don't do it, it deletes all NBT data in every file in the world folder) this is really annoying.

This problem need to be fixed, I can't join most of the server. And every days, this problem is getting worse and worse.

This problem indeed needs to be fixed. I can't join my server at all, and IF I can, I just get kicked out again. Is there any temporary solutions for this problem?

Happens to me on playmindcrack all the time. My speeds: 50mb down, 12mb up. Able to handle other pc/console gaming + voice without issues. Playing on mac client if that makes a difference. This one is bumming me out. My timeline for when this started matches OP.

Edit: Wanted to add, my connection to the internet goes down and I can't access anything after I get this error. Disconnecting/reconnecting to the network immediately resolves the issue.

Confirmed in 05a. Haven't tested 05b yet.

This is still a pretty major issue in 1.7.4 for me and my server. 😞

Do we have a way to reproduce this problem?

I get the feeling that a couple of different bugs are being represented here, given the variety of ways people have come across this issue. This isn't surprising, given the generality of the error message. Perhaps those of us with the problem can do some more experimenting to see if we can come up with a way to replicate our problem from scratch? If our experiments lead us to multiple, very different ways of replicating the error then we could look into splitting the issue into separate issues and resolving each one individually. I'm committed to getting this fixed though; this really messes up the experience on our vanilla server.

I will have to do some tinkering with our server, but here is what I've noticed when this has happened to us on the two different servers I play on where this error occurs:

1. Old terrain (Pre-1.7) exists on the server.
2. New terrain (1.7) is being generated quickly when this error begins to occur; by quickly I mean the player is usually either boating, on horseback, or using a speed buff and running mainly in one direction for quite a while, all while generating new terrain.
3. Once the problem begins to occur, it occurs repeatedly until (a) the player stops generating new terrain, and (b) leaves the new terrain that has been generated after the error started occurring.
4. Anytime a player returns to the area where the error was occurring, the error begins to happen again for the whole server until the said player leaves the area again.

Again, I'll play around with it and see if I can get this to happen consistently. I'll create a test server with these conditions, and see if the error occurs for me. If anyone else can experiment with this, or add anything to the steps that I mentioned, that would be great.

We are seeing similar to what Kyle is explaining. On a brand new server we don't see it very often. On a server that had pre-1.7 terrain we get this every time someone goes off to explore new chunks. If everyone stays in already loaded chunks we see it rarely. It does not seem to be related to player connection to the server as the entire server gets kicked no matter who is exploring new chunks. We have 16 GBs of ram on the server and the entire server is inside a ram disk to try and increase performance. Under full load the server rarely uses more than a couple GBs of ram so it doesn't seem to be related either. We also will randomly see it other times but the error is so generic it's hard to tell what is really happening. All of these issue did not happen pre-netty implementation either.

There's a Mod comment here saying Mojang can't really do anything about it... ?
Why is that? With hundreds of replications via different systems, setups, etc - and something that was clearly introduced in a newer release and never happened before... Mojang can certainly do something about this.

They mean they can't directly do anything about it. I work in software QA and we have similar problems when using software pieces or libraries made by a 3rd party. If there is a flaw in netty (which it's sounding like the main issue) and not in the implementation of netty there isn't anything Mojang can do directly to fix the problem. Instead they have to either change how they use netty, go back to not using netty, or pressure the people making netty to fix their own problems. This sort of thing is quite common in software development though it is a bit strange this is taking so long for a solution to be determined.

I was able to reproduce the bug with the flick of a lever:
Video: https://www.youtube.com/watch?v=odxXrrAoBHs [DUTCH] Skip to 3:02 to see the bug in action
World Download: https://dl.dropboxusercontent.com/u/40635933/io.netty.bug.zip

I starting following Grum's Twitter feed (this issue is assigned to him). On there, he was recently claiming there was nothing to fix, that it was network issues causing no data in the packet. As of this morning, he seemed to embrace that it might be a bug but that they haven't been able to reproduce it, so there's nothing he can do. (Thus the recent comment on here looking for a way to reproduce it, I presume.)

I haven't been able to determine the exact factors that contribute to this happening, but what Kyle Tuft wrote earlier today looks to be very similar to what I've seen on our server.

EDIT: I see Kevin van der Burg beat my comment with a reproduction of the bug! Well done, sir! Well done indeed! I just wish I spoke Dutch or whatever it is so I knew what you were saying.

Users on my server have occasional issues with the bug but I am completely unable to log in without crashing the server. Could it have something to do with the sh*tzillion command blocks and hopper clocks I have running in that area?

Andrew I believe that triggers the same error but for a different reason. I've this same error message when overloading the server with infinite villagers or tons of redstone but I think it's different. You can trying using commands to move your character somewhere else to see if you are just overloading things.

I think there might be two issues at hand, one is that the server can get too busy to send you any data for some period of time (causing a timeout) and the other is that the connection you have to the server is so bad that there is no data for some period of time (causing the timeout). Neither is a 'real' bug, but we might be able to somehow fix the first issue.

How beefy of a server would we need then? Like I mentioned earlier we are running on a ram disk and have 16 GBs of ram on the server and it never even uses more than a couple GBs on full load. The server is on a 250 down 60 up line. Some of our users are connecting on fiber so that should be plenty good for Minecraft. Even with just one person on as soon as they move to a new chunk it crashes.

I always getting this error on some servers, other servers are fine.

I think there might be two issues at hand, one is that the server can get too busy to send you any data for some period of time (causing a timeout)...

Joseph, given your specs I would say that this is the issue you're facing, not a bad connection to a server!

The particulars of my situation: Regular players on my server have occasional issues with the bug. When I log in only one chunk loads. Within this chunk no mobs are moving and no redstone signals move. Commands are unresponsive; I can't teleport, kill myself or speak. I have three command blocks on circuits and I know one of them (for summoning a mob) has a typo in it that shouldn't cause a problem of this magnitude. After 30 seconds of getting nothing accomplished the error code pops up for everyone on the server and the server usually crashes. I have old and new terrain and the area I am in is new terrain.

Most of the time you need a damn good processor (not a multi-core one unless you downright need it). Something in the 3.6-4.2 ghtz. RAM is good for holding world data so if lots of people are going to be in lots of different places then get about 8 GBs for about 10 people at most.

And Grum, those can't be the issues (at least on my server) because in 1.7.4 it works fine, but then when you update even my client that is running with the server on the same machine disconnect and I am unable to turn the server off through the stop command.

Additional information: One of my regulars tells me that when the bug boots him he cant log on until I reboot the server. Also, when I spawn in my one-chunk prison there is a redstone signal powering command blocks. Is it possible that one of the blocks(the one with the typo?) is causing the crash?

This continues to happen to us intermittently and I haven’t been able to pin down a specific cause, but I can comment on some of the suggested contributing factors.

1. Old territory: we started a new 1.7 world - there is no old territory

2. Exploration: being a new world there was lots of exploration, so this could be a factor

3. Connection speed: might increase chances of it happening but also happens across gigabit LAN

4. Command blocks / redstone: although we now have some of this, it happened back when the world was new

5. Java parameters: I was running -XX:+UseG1GC -XX:MaxGCPauseMillis=200 and will try without -XX:MaxGCPauseMillis=200 though it seems a little ‘voodoo’

6. Restart: helps when logins are totally failing after this error, but sometimes the server seems to ‘recover’ on its own. It’s set to restart overnight anyway.

This io.netty thing is a curse! It's unsolvable, and annoying as heck! It is less frequent lately, last I checked though.

Has anyone figured how to fix this yet?

I haven't found any way to fix this. But some how the connection to some unable connected server (Internal Exception: io.netty.handler.timeout.ReadTimeoutException) is way more better and I can play it. I don't know if you guy know this but I think there is something with the "MineChat" App, after I used it, I can now play my server.

In my server, it crashes when a rail is placed. With an io.netty.handler.timeout.ReadTimeoutException also

My serber is currently having this issue for all players 😞 the livemap is up and everything but shows offline and nobody can get in.

We are using 14w07a on our server, this has become more of a problem recently. It often causes a server-wide crash, which requires a complete restart. A few snapshots ago, this was really only affecting me, as I had a poorer connection; but now it has become an issue for all players.

There is an issue with 07a that affects some ppl in the way that nobody can get on and others like myself when i used it, caused the map to be unstable an eventually crash the server, but in terms of the 07a part of things, its a known issue.

You should add 1.7.2 to the fix versions list.
This bug is very annoying in 1.7.2...

Since this thread is very long, I just wanted to point out a solution for certain servers experiencing this issue. YMMV.

Step 1: Stop your server.
Step 2: Look for the file in your server data files called data/Mineshaft.dat.
Step 3: Rename it to Mineshaft.old
Step 4: Start your server.

If this "solves" your problem, you might have to repeat this periodically, as the file grows, depending on how much players explore. But if this does not solve your problem, you should rename Mineshaft.old back to Mineshaft.dat, just in case the file is ever used for anything some day.

You can easily get this problem by using a Laptop, play on a server and then close the screen, after that, open the screen and you will see the problem appear.

Arkov that is completely different. For most laptops by default, closing the screen also disconnects your Internet. Disconnecting your Internet will cause you to lose connection to your Minecraft server >.>

Have been getting this error on a Snapshot server since the 1.7 snapshots were being released. When someone tries to explore it kicks everyone who is on the server and gives them all this same message. The server is currently running 14w08a at the time of this message.

I have the same problem. To help mojang find where the problem may be, ill describe the situation it happens in with as much detail i can.

• I was trying to connect to an friends server, using hamachi.

• When i hosted the server instead of my friend, the same thing happend to him.

• I have an very good internet connection

• This happens allot, to the point where we can't play togetter anymore

• I play only on vanilla mincraft and have no mods installed (including bukkit).

• I play on an windows (hp) laptop with an very good graphic card and with windows 7.

• Using wireless internet or cable results in the same error.

• Things iv'e tried( and the server host as well) that didnt help:

• Restarting the server

• Restarting minecraft

• Reinstalling mincraft

• Adjusting the video settings

• Deleting my texture packs

• Restarting my router

• Reinstalling Hamachi

• I have no other programs open during the time i'm playing on the server (except for hamachi).

• I have my mincraft account since the very early stages of mincraft.

• I am playing on the latest minecraft version (1.7.5) but it has bin happening for me since 1.7.2.

• Once it happens it keeps happening to the point where i'm unable to play anymore on that server.

• I have never messed with the minecraft files (except from the recource packs map).

• I am from Belgium (don't know if thay really matters, but the more info you have, the easier it must be to find the problem)

Thats about everyting I can think of right now. I hope this helps. If I thing of more thing to add, ill edit this post. And i also hopes this gets fixed soon, because it's really effecting my ability to play minecraft to the point where I not even want to start playing minecraft with my friends anymore because I know it won't work anyway.

Friendly greetings,

Tijl

I've been having this prob on my server as well
it only seems to happen when I travel long distances in the game.
kicking everyone from the server giving the
"Internal exception: io.netty.handler.timeout.readTimeoutexception"
to everyone. Its really odd because if everyone doesn't travel through a lot of chunks.
it doesn't happen..
I hope this helps
btw my server has 2 3.6 ghz processors and 8 Gb of ram.
so it should be able to handle minecraft with out issues.
and my internet speed 56mbps down with an 11.3 Mbps up and a ping of 20 ms
so its not my internet..
Hope this narrow down the bug tracking good luck n.n smiles

I have this problem when trying to connect to a singleplayer world shared over LAN.

I get this error every time i try to log on, not just occasionally, as seen here.

I have an idea how about mojang re-writes minecraft without using java? Cause I wanna play multiplayer with my friends again. I have gotten this error since 1.7.2

Andrew Clarke: You can use Spigot server, as that doesn't use structure saving that is causing this exceptions. You can use it as a drop-in replacement for the minecraft jar.

Haha, that's pretty funny, Andrew. I like your jokes. 🙂

What about mojang tell us what this is about? Cause its wierd.... I can join multyplayer servers at like 1 am til 13pm those times i dont get the error the rest of the day i do so mojang tell us how to fix 🙂

It would seem this has become more prevelant in 14w10c then ive seen it since Dinnerbone re-wrote the code back in the 13w series of snapshots for networking, but im sure there working on trying to fix this issue

Addnig my own comment here. I hope this becomes popular enough for Mojang to look into a resolution soon.

Sometimes I get Lag (not FPS lag, it's like server lag, a signs of Internal Exception in Multiplayer) in Single Player.

Started seeing this recently. Client and Server are both 1.7.5. Server is local. Friends have no problems, just me. It happens consistently. I had hoped that bumping RAM and automating an hourly restart would make it less likely to happen. But, neither seem to help at all.

Most annoying when it happens at night. Your player can be left in the game and will be killed by hostiles if you are unable to log back in quick enough.

I've had the same issue for the past three days.
Good internet, good computer. It only seems to happen on one server and it doesn't happen all of the time. I reinstalled Minecraft, Java, did all the updates my computer needed, restarted my router, did a direct connect to my router... nothing.
It's usually just awful lag or I'll get disconnected with "Internal Exception: io.netty.handler.timeout.ReadTimeoutException". I also get d/c'd if I tab out of MC (I can prevent this by going into the options window- not sure how long it delays the disconnection as a whole, though).
The server was having some issues itself, but after it was rebooted, it seemed to be fine for everyone else, but not me. My friends all have no issues.
I did fine yesterday (hardly any lag at all!) but the day before and today it's almost unbearable. My ping on the sever varies from 80~150 (average for me) to 3-4K (which is about the time I d/c or log off since I can't really play). Server owner doesn't seem to understand my issue and thought the reboot would fix it all. I also disconnect when my ping is around 120-140ish for some reason.
I've had no other issues on other servers and I had no issues on this one before three days ago.
I DID notice Java had updated the morning my issues started, but an uninstall, installation of an older version, and then installation of the current/newest version did not help at all.
I have no idea what to do, but I hope it gets fixed soon or someone figures out what makes it go away. P:,
Not sure if it helps, but I figured I'd put what I tried to see if it leads anywhere.

EDIT: I also get an error message saying "Internal Exception: Java.io.IOException: An established connection was aborted by the software in your host machine."

I have also been having this problem for a month now. Unlike the rest of you, I have this problem on every single server I try to join. When I first join a server I am I can stay connected and play for as long as I stay on the server. But as soon as I leave, I can't stay connected. I log in, and chunks will load, but people won't move. After I few minutes I am disconnected by "io.netty.handler.timeout.ReadTimeoutException". And like I said, this happens on every single server I get on.
I do have a good computer with a good connection to internet, and every solution I have found does not work. We need a sign that this is being worked on.

I also have this error, on only 1 of multiple servers I visit. I am also the only one on that server with the issue.

I hope this issue gets resolved soon, cause I can't wait to play on servers again with my friends (happens on all servers for me).

I was cleared off this issue for a day, but then it came back. Hoping for a fix. This is frustrating. I can't play on any server at all.

This happens to me on the ItsJerryAndHarry server

I believe we will see a profound reduction of io.netty.handler.timeout.ReadTimeoutException due to the fix of MC-33086. If there's a snapshot tomorrow, we shall see.

I was cured off of this for about a week or two, but then it came back. I'm rendered unable to play once more. 😞

sigh. The problem seems worse with the 1.7.7 updated. Before, I was able to get around it by restarting the client and the sever. Now, it is much more difficult to get rid of. A few times, by restarting both client and server, then logging into a single player game, then back into the server helps. But, even then, it doesn't always come back.

Driving me nuts.

Okay, Everyone, it is now all clear to me.
Get an actual log of what goes on in the scripting before, during, and after the exception has occurred. After that, i can try and use my knowledge to give suggestions.

Major Edit:
It seems that the possibility becomes quite high after it is achieved once. It might be that the game attempts to switch files and ram, and shuffles two files needed in two places back, then "remembers" the pattern for "convenience" without even knowing it is causing the error. Or.. it could be the work of the villager overlord serving us... wanting revenge... Okay, joking. But really, see if my theory is valid.

play.itsjerryandharry.com:

[07:53:44 INFO]: Client> [07:53:44] [Netty Client IO #1/ERROR]: Invalid server icon (unknown format)
[07:54:00 INFO]: Client> [07:54:00] [Client thread/INFO]: Connecting to play.itsjerryandharry.com, 25565
[07:54:02 INFO]: Client> [07:54:02] [Client thread/INFO]: [CHAT] --------------------------------------------------
[07:54:02 INFO]: Client> [07:54:02] [Client thread/INFO]: [CHAT] Welcome to ItsJerryAndHarry's server, koolTbyrd
[07:54:02 INFO]: Client> [07:54:02] [Client thread/INFO]: [CHAT] Check out our website! http://www.itsjerryandharry.com
[07:54:02 INFO]: Client> [07:54:02] [Client thread/INFO]: [CHAT] --------------------------------------------------

Apparently, It's the Icon. :/

This happened to me, after this the server window becomes unresponsive and I have to shut it down from the task manager. It also kicks us off.

[18:42:44 INFO]: Starting minecraft server version 14w03b
[18:42:44 INFO]: Loading properties
[18:42:44 INFO]: Default game type: SURVIVAL
[18:42:44 INFO]: Generating keypair
[18:42:44 INFO]: Starting Minecraft server on 192.168.2.10:25565
[18:42:44 INFO]: Preparing level "Normal World"
[18:42:44 INFO]: Preparing start region for level 0
[18:42:45 INFO]: Preparing spawn area: 0%
[18:42:46 INFO]: Preparing spawn area: 73%
[18:42:47 INFO]: Done (2.657s)! For help, type "help" or "?"
[18:47:09 INFO]: UUID of player ObsidianMinor is ba7b33e1a4e149a394feaa894c52d071
[18:47:09 INFO]: ObsidianMinor[/192.168.2.10:55304] logged in with entity id 1200 at (-122.53346217859138, 65.0, 249.87257538849914)
[18:47:09 INFO]: ObsidianMinor joined the game
[18:47:32 INFO]: UUID of player CallMeGI is ef63e4007ad94feab4645631d9535346
[18:47:32 INFO]: CallMeGI[/70.112.62.154:57965] logged in with entity id 3710 at (94.5122214212057, 53.0, 0.36600269876827796)
[18:47:32 INFO]: CallMeGI joined the game

So Maxwell what would be a fix?

Why does this glitch only happen to me on some servers not all of it?
(pls. answer my question)

@Andrew, Hmm. I thought there would be some sort of clue. did you force a crash with
F3 + C for 10s?

@MJ Cortez, This Exception is quite difficult to solve. the crash coding isn't showing anything. I used to experience this when my internet was really hiccuping, or that...
Aha! It might be that two IP's afflict one another due to their similarity.
Ehh. Maybe not. 😛
Well, analyzing the file you have sent ever so kindly...
You need to try and reproduce this, and find how common it is at certain times.
(NOTE: I used to get it, but i thought that "TimeOut" meant either
1. I went AFK too long.
2. I lagged too long.
3. Servers are just jerks.
After i found out it was a bug, I wasn't too shocked. Most certainly, i don't get it now. The only time I get the error is when too many people are lagging, or when there was too much modification to the server, causing too much lag. I wish I could solve it, but it seems there is no unusual behavior with the report.
@CraftyMiner, That's interesting. VERY interesting.

Okay, guys, i will try and cause the Timeout Exception, but i need to know how to trigger it. I know it sounds simple, but i don't remember how to simply cause it anymore, since in 1.7.9, it seems that I don't get it.
(NOTE: Confirm for 1.7.9, as I need PROOF that it still occurs. (at least in any version that is or past 1.7.9, pre-release or not)

Not sure if I can confirm this exact error still occuring in 1.7.9 but it's something similar and might be related.

Here is what I know:

I've got two servers running on a virtual server on my root server. They were both version 1.7.5 and I'm using Multicraft to manage the servers.

Two days ago the disconnecting started without apparent reason (no changes have been done to the server). Players were kicked, receiving a "java.io.IOException: A connection was throttled by the remotehost" on their minecraft screen. This happened on both servers and started around the same time.

My console always showed the same thing for every player:

[23:01:02] [Server thread/INFO]: MissPepperpot lost connection: Internal Exception: net.minecraft.util.io.netty.handler.timeout.ReadTimeoutException

Nothing else, just a bunch of those messages for every player that got disconnected. It was the exact same thing for various versions of craftbukkit and spigot on 1.7.2 and 1.7.5. and also with java 7 (update 55) and java 8 (update 5) running on the server.

Now I recently updated to 1.7.9, hoping that it might eliminate the problem. But still, players get kicked from the server. The message on the minecraft screen is still the same. Console output changed though:

[23:07:06] [Server thread/INFO]: MissPepperpot lost connection: Timed out

No more io.netty but the phenomenon is still pretty much the same. All players get disconnected at the same time, the server keeps running but takes a moment before being available again.

The error is still random and I can't fathom how to reproduce it except by waiting for it.

Not sure if this does help you in any way. If you need any further information, please let me know.

It may be a problem with world data. Based on what Jenni said "I recently updated to 1.7.9, hoping that it might eliminate the problem. But still, players get kicked from the server.", it means that it does not get fixed with updating. Joe said "I get it on both the 13w41a and 13w41b snapshots." same world file? I updated to a snapshot and had the bug happen, forcing me go back down and use a back up I had made before. I have never encountered the problem since then. Tijl said "When i hosted the server instead of my friend, the same thing happend to him." using the same world. So maybe the server sends a faulty world file to the client and it disconnects.

But the error is made in many different ways so this may not be the cause.

Just do add info to what Aaron said about world issues: My two servers run the same world. I use one server for playing and one for plugin tests. The test server is a copy of the main server. But the last time I copied the main server to the test server was weeks, if not months, before the issue occured for the first time. A lot has happened on the main server's world since then while the test server is essentially still the same. And still the error started occuring at the same time on both servers. So if it's a world issue it would take a while to surface.

I'm going to delete the world files on my test server tonight and keep all the other settings to see if it keeps happening with a fresh world.

I had this problem on my home server...starting from snapshot 14W11B. It would either kick some or all users off after 30 seconds, or work perfectly fine for days at a time. Restarting the minecraft server jar usually sorted things, but not always.

Players in the nether didn't get disconnected as often...so after trying a bunch of things, it turned out the livestock Tower in the overworld was causing the problem (14x14x40 block tower, with 7 levels of different animals / coloured sheep)

After killing off enough pigs and cows to give 3 stacks of bacon, and 2.5 stacks of beef, the problem disappeared.

I have a similar issue, except I am completely unable to join any multiplayer servers if my .minecraft file is created by my own minecraft account. If its created by a friends account, multiplayer works =/

Affects 14w25b: after the server runs for a while, everyone is kicked and then no one can join anymore, getting this exception instead.

Normal. Some servers are offline some of the time, and when it turns offline while some people are playing, you get that.

@@unknown: The server is still running, and using the list command from the console reports the player(s) who were online at the time the error occured as still online.

I'm seeing this myself after I tried to log into a server on 14w25b and couldn't get in (was getting the above error). If I start the same server version on my own computer, I get an internal server error message the first time I try to log in and then the ReadTimeoutException every time after that until the server is stopped

I cant join any public minecraft servers at all. here is what happens: https://www.youtube.com/watch?v=MbuCT599J9k
i dont even know how or why this happens. any help would be VERY much appreciated.

@@unknown: I don't think your issue is the same as this one. You might want to open a new issue for it.

I think that it is the player data, I had to delete all of it to fix my server.

History: Updated to 14w26b, then used a pre-w26 back-up world with 14w26c. Worked fine all night. Next morning when trying to log in I got the io.netty.handler.timeout.ReadTimeoutException with 3 separate accounts. The only error on the Server side is "[User authenticator #1]/INFO: UUID of player (player) is (string).

Tried deleting player data as well as user cache. No change.

Tried loading my pre-w26 map with 14w26c and it is loading again, however my 14w26c map, which of course I put about 18 hours of work into in one day, will no longer load, even with the 14w26c snapshot.

Sorry for lack of detail this is my first post here.

EDIT: I tried to open my broken 14w26c map in MCEdit, and it opened, so I flew around the map a bit until it started to lag a lot by a new mob arena that I created with command blocks. The entities show up as red blocks in MCEdit and before logging out previously my son had decided to change all of the Zombie heads to Sand blocks. I don't know if that had anything to do with it but I selected the area in MCEdit and used the Delete Entities option and the lag went away and the map now once again works using snapshot 14w26c and I was able to salvage all the work I thought I lost. I know this isn't an MCEdit forum but it allowed me to correct the issue.

@unknown, the latter issue is MC-59294

I only get this error on my favorite server (ninescraft.net) and ONLY on my home WiFi but if i was to go to a library/Coffee shop/Friends house then I could join Is there anything i can do to fix this? Because this is my favorite server

yeah i get this error only on my home wifi aswell

Weird stuff is happening.
http://i60.tinypic.com/1i0bog.png
This is the server I'm trying to join. I edited the description because it had its IP in it, but it's a private server.
You see, there is a guy online. He is online non-stop since yesterday.
And when I try to join...
http://i62.tinypic.com/d5xr7.png

Affects 14w28a.

I have a good connection, but I only happens in 3 servers that usually play, and oddly entertainment industry as one that has separate FTB, I can not connect in and have the same problem

Affects 14w30c also.

http://i58.tinypic.com/168ec87.jpg

(in 14w28b i didnt have this problem to connect to same server)

now it happen always in 14w30c

I haven't posted for a while now but one aspect of this defect seems to have been fixed a while back with how the .dat files were being read. This was the issue where people on a server moving into new chunks would kick all players with this error. I've done a lot of exploring recently and this doesn't seem to happen anymore. Unfortunately this error shows for a multitude of reasons and the others seem to still be happening to people.

I have played mine craft on my own server for hundreds of hours without any issues. After taking a break for about half a year I decided to start playing again so I downloaded MC1.7.10 and the latest server version as well, set it all up as usual and was playing with my friend the whole day yesterday.

We wanted to play again today but all of a sudden one of us can't connect anymore, getting the dreaded timeout error message.

Here is the setup:

Host computer is a Windows pc which also serves as client for one of us two players (is powerful enough with 16GB RAM, worked fine for hundreds of hours of play without any crash at all).

Second computer with second MC client is running on a Macbook Pro, connected through WLAN.

Port forwarding is enabled, even though I read it's not necessary for LAN games, we always used the server to connect to as if we were at a different location and that always worked for months!

So now, I can't connect to the server anymore from the Macbook Pro (WLAN connection). The Windows pc (which is also the server) can connect just fine.

In the meantime I have also tried to share a single player game from the server pc as a LAN game. On the Macbook Pro I can see the game but when I try to connect I also get the timeout error.

Now I've been reading through over a dozen threads on various websites and tried all possible fixes/suggestions for fixes, have checked firewall etc. but can't see the reason why all of a sudden it's not working anymore!?!

Once again, we just played yesterday for like 10 hours straight without any issue, on the very same setup and I haven't made any changes to it.

The only last thing I can find where there might be a problem is port forwarding. On the Mac I checked port forwarding through this website:
http://www.yougetsignal.com/tools/open-ports/

And it says that port 25565 is closed!

Which A) is weird since I enabled port forwarding directly in the router and always worked
and B) at least should not have any influence on playing a LAN game as per official info on how to play Minecraft in LAN

The router I'm using is a Netgear, modem is a Cisco (without built in router).

Any suggestions would be very helpful. I paid specifically for two MC accounts so we could play at home with my friends and now it's not working at all, wasted money 😞

https://www.youtube.com/watch?v=qcW-BqT32GM

that's what happens 😞

@Marc Oberdorfer

I have pretty much the EXACT same issue, right down to it saying the port isn't open. I bought a Realm and now we can't access it. Very frustrating.

I've seen this happening on my server since 14w31a and it just happened again after updating to 14w32d. Restarting my client always clears it up though.

As it is now it seems that we have solved this on our server. I can not be 100% sure yet, but it seems like it. Atleast it haven't happend since we made some changes to the server.
What we did was that we changed to the latest version of java 7 (from oracle) on the server and started to use the following startup script:

JVM arguments

java -Xms2G -Xmx2G -XX:+UseG1GC -XX:MaxGCPauseMillis=25 -server -jar minecraft_server.jar nogui

The reasoning is that the G1 garbage collector does a better job of not doing full collections while the client has to wait (and thus getting disconnected).

Breakdown of the above is as follows:

Minimum and maximum memory, change the 2G to how many GB the server should use

-Xms2G -Xmx2G

This is to use the G1 garbage collector

-XX:+UseG1GC

This is the pause time G1GC aims at, and I have set this to 25ms to be half the time of a tick, leaving time for the regular tick to happen.

-XX:MaxGCPauseMillis=25

(The rest of it should be obvious.)

If someone that have this problem could try with the latest java 7 on the server and the above parameters and get back here with your results, that would be great.

Hey everyone, my friends and I run a small vanilla server for just us and we encountered this issue. No one could log in without being disconnected with that error code. I had my friend that ran the server go into single player and teleport his character far away from where he was. When he loaded the world again on the multiplayer server he was able to play without being disconnected. After he teleported back to our houses he jokingly said "I bet its all these cows we have." I just laughed and told him to kill all of them incase it was. It fucking worked. After he killed all of our livestock we were able to log back on to the server. My theory is that we hit some sort of entity cap or some shit and the game just didn't know what to do so it disconnected us. We had like maybe 100 cows and 50 sheep in a 30x27 pen. Not sure if this is any help for you guys but it worked for us.

Hey guys.
I was looking through my installed programs, noticed there was something called "offerswizard network system driver"
I uninstalled it, because all it apparently seems to do is send web traffic.
Soon as I did that, my Minecraft worked fine! Perfect!
Hope this works for you all 😉

@DarkCharizardXD
That sounds like your computer has been infected with a virus. You might want to do some virus scans!

Tryed JVM Arguments "java -Xms2G -Xmx2G -XX:+UseG1GC -XX:MaxGCPauseMillis=25 -server -jar minecraft_server.jar nogui" as suggested by Pierre Waldén, the 11th of August.

That doesn't work !! Thousand of Java errors are still generated ...

Just for information .....

Got the same damn problem since I've started playing on the 1.8Pr1 then 2 and 3, I had this problem before in 1.7.10 modded also but it only happened around 1-2 times each month, I had plenty of servers since version 1.2.5, we never ever changed the server computer is the same as before, ISP speed is still the same (Fiber 50mbps/50mbps fully tested with a ping of 8ms) Its starting to really be annoying, can't believe they did something that cause that problem and never fixed it since before the 1.7 release, it was actually in the snapshots of the 1.7, weird thing is we had a server in the snapshots of the 1.7 and also one in most of the snapshots of the 1.8 (we stopped at 14w21b to play modded 1.7.10 for awhile without any problems at all) and I've seen that error a couple of times in the past but it was actually happening 1-2 times by month I would say, now it happens every 15-30 minutes most of the time. I just got killed by a zombie (my ghost player, not me, but once I've disconnected and connected, I was dead) because of this bug, thankfully we're not in the Nether yet, I would have deleted the whole server thing if I've lost all my valuables in lava in the Nether because of a bug like this, I'm not the kind to rage quit when I die usually, but if it happens because of this, I don't know what I would do.

And for thoses that would say its my ISP (the server is at my brother house, around 10-15km from my own place), look here : [URL=http://www.speedtest.net/my-result/3723195403][IMG]http://www.speedtest.net/result/3723195403.png/IMG/URL

@unknown
When you said that my suggestion did not work, and that you get "Thousand of Java errors", I think that either you did not do exactly what I wrote, or you have some bigger problems.

Let me ask you some questions to try and help you further:

• Did you do this on the server? (Doing this on the client was obviously not the intention)

• Did you update to the latest JDK (java) on the server? (Older java versions wont work, since G1GC is not implemented there)

• How much memory do you have on the server? You need to have around 3GB++ to use those parameters. (If you don't have that much, you need to use lower Xms and Xmx)

• Does this happen on every world on that server or just on one?

• Have you ever had this working without getting these errors?

• Do you really get even close to 1000 error messages?

• If not, how often do you get them and when?

What io.netty.handler.timeout.ReadTimeoutException tells you is that you get a connection timeout. This can be caused by several things, (like for example if you have internet problems, if you are downloading some torrent or something like that). It can also be caused by the server (or client) being busy doing something else for a long time not getting the chance to respond and thus causing a connection timeout. On the server side, this can in some cases happen for example during a massive garbage collection. What the parameters I posted before does is that it uses another garbage collector that does a better job of trying to do short garbage collections often, and in a totally different way, trying to avoid full collections. (I cant explain exactly how G1GC works here, so if you want it all, I suggest you google it).

Anyway.. The reason I set it to 25 ms is that if it keeps that goal (you need to understand that that is a goal, and not a promise from the GC), then you will have it take half a game tick, and there is still some time for the server do do whatever else it needs to do during that game tick. (This is under optimal conditions ofc)

Since I did this on our server, we have not had one single io.netty.handler.timeout.ReadTimeoutException, so I would say that it can help in some cases, even if it is not helping in yours.

Remember... If you are getting Java errors of any sort that you either don't understand, or you think shouldn't happen, try downloading the latest Java version both on your client and server before testing anything else.

Pierre Waldén

Come put your insight in over here http://www.reddit.com/r/Minecraft/comments/2f9sxg/dear_dinnerbonemojang_whats_the_deal_with_ionetty/ I'm trying to figure this issue out too but on Java 8

Now its not fixed in the official 1.8 and its getting on my nerves so much, can't go in the Nether, can't go cave mining, can't do anything were I could die because of this stupid bug, please fix it, its not on my server fault, not on my ISP either, you screwed up something and now I can't enjoy the game in survival mode without worrying because I neve know when this bug will kick me out of the server, hell yesterday I was just cooking stuff in my furnace without moving for more than 20 minutes, there's no entity near my cooking base, then I got kicked out again with this stupid error. I guess complaining here is useless but I never know.

Soooooo

I have had this problem FOR OYER ONE FING YEAR>

>??

WHERE IS THE SOLUTION!

This problem just started for me when we upgraded the server to 1.8. The server admin does not get this problem.

I updated Java to the newest version, which does not resolve the issue.

I'm able to login, but not interact with chests/beds. I can interact with doors & blocks, but the blocks do not appear on the ground and I'm booted with the error before I'm able to pick anything up. The game is unplayable in this state.

had same issue on 1.8 ours was solved by thinning the animal population on the farms in the local area. apparently they were utilizing too much resources and the server was prioritizing it above client responses leading to the issues

For me this issue also started when switching to version 1.8. I get this error whenever I go through a nether portal. Instead of the "Downloading Terrain" message I get the "Connection Lost: Internal Exception: io.netty.handler.timeout.ReadTimeoutException" error message. The server and the client are in the same network connected by a switch (I am the server admin), so there should be no problem with the network connection. Even more interesting is the fact, that a friend of mine who is connected to my server over the internet, does not experience this problem.

Some other observations: After starting the minecraft client, I can connect to the server without any problems. However, if I disconnect from the server (on purpose, e.g. when I go AFK) and want to reconnect, I get the above mentioned error message. I have to restart my minecraft client in order to connect to the server.

@unknown: I have some questions for you.
Does tabbing out of the game or doing something else, like watching youtube (or whatever) increase the rate of this happening?
Also, do you have a lot of other programs running on your computer while this is happening?
Is your CPU at 100% when playing minecraft?
What is the setting of network compression of the server?

Are your incoming ports for minecraft being blocked? Cause mine were and my internet provider unblocked them and the error was gone.

Pierre Waldén: I haven't tried tabbing out or doing something else (like watching youtube) yet, since I have my second computer (which also runs the server) for these purposes. What do you excactly mean by "increase the rate of this happening"? I lose the connection every time I go through a nether portal, but this is the only scenario for me.
On my laptop I only run the minecraft client and skype for multiplayer communication purposes. The CPU usually is not at 100% when playing minecraft. However, if I lose the connection (e.g. after going through a nether portal) and I try to reconnect to my server without restarting the client, one out of two CPU cores goes to 100%.
The server network compression threshold is 256, this should be the default value.

Andrew Clarke: The server and the client are in the same network (local area network), connected by a switch. Both computers are in the same room - so for me there is no internet provider involved. However, I still get the error. And as I said, my friend who is connected to my server via the internet, does not experience the problem with the lost connection

Ok this might be some help to bukkit/spigot or mojang team member
http://netty.io/

Since bukkit and spigot are now dead (google is your friend, you'll learn all the bad news quickly), I don't think we're going to see any kind of bug fixing like that Io.netty error anytime soon, Mojang needs to develop an alternative to bukkit or spigot ASAP, the life of all the Minecraft servers is the key so I think we're going to wait for awhile before they even think about fixing any kind of bugs.

They already are, (google is your friend, you'll learn all the good news quickly).

People need to relax about this "Error" because that is exactly what it is. An error message. It is not a glitch or a bug. It is an error message that is telling you that the asychnronous netty event timed-out.

Even if Mojang fixed 110% of every glitch and bug in MC some people would STILL see this ERROR MESSAGE from time-to-time, when their communication with the server in question has timed out (usually at log-in).

Typical causes for this ERROR MESSAGE:

1) The server sucks and doesn't have enough RAM, or is bogged down with buggy plug-ins, or the server is lagging because it is trying to process too much at once (Admin built a super-crazy redstone clock, too many entities on the map, etc).

2) The End-User has a crappy computer and is taking too long to load the map.

3) The ISP or internet connection of the server itself is bad or slow or bogged down(in the case that it's normally a good connection)

4) The ISP or internet connection of the player is experiencing similar problems as above.

To conclude this post there are basically a ton of reasons you may see this error message, and those reasons themselves are what need to be fixed, not this error message. I several times solved this issue on my server simply by doing a /kill @e command.

Ben Campbell, you didn't read all the comments I've made, read my server specs description, read the ISP I have, on both the server and the client they are ones of the best we could have, and even my brother got the problem while at his home, the server is in his bedroom and he has a wired connection between the router and the server is also wired to the router to avoid wireless problems. Both our machines are more than able to handle Minecraft, we had a heavy modded 1.6.4 server based on FTB plus a bunch of extra mods, and never ever experienced any problems, even with an overload of logistic pipes and such. And now the same server couldn't handle a vanilla Minecraft 1.8, this might be an error message, but I've only seen it 1-2 times and only since Minecraft 1.7.X serie, and since I've upgraded to 1.8, I keep getting it, this is ridiculously annoying, they can fix this one I'm 100% sure, but they are busy with something else and don't really care about bug reports.

Ben, you have some good points, however the fact still remains that this wasn't a problem for many of us until the pre-releases of 1.8. So obviously something on their end has changed to cause an influx of this error.

I would add to your post by saying that there isn't one solution. After doing research on this error for months I've found that people get it for 1,000 different reasons so there most likely isn't a single fix. My server, for instance, gets this error when I either have too many animals, or I breed them too quickly. From that point on the server is goofed up for upwards of a week, or whenever it decides to start working again.

Edit: Something else to add. I had previously been allocating 2GB or 3GB of RAM to my server, I just reduced the RAM to 1GB and it's working. Could it be that the computer is running the server "faster" than the network can and it never catches up?

@McDodge: Concerning Server-Client wired in the same room I had this issue as well and found out my map was corrupted. I used MCEdit to manually delete the corrupted blocks (actual single corrupted blocks, typically entities gone bad for some reason or another) and then the server worked again. This goes back to an earlier issue with map corruption that was prevalent in the snapshots around the same time Bunnies were introduced. I didn't have time to go back and look for your server specs but have you tried using a fresh map or using MC edit to check for fixable map corruption?

@Kyle: Concerning RAM and too many entities. I built a machine that spawned way too many zombies and got this error constantly until I used MC edit to manually delete entities from the server. I also had a lot of issues trying to max out the RAM my server was using. Part of the problem is that if you dedicate too much RAM to the server then the computer can't commit memory to the processes it needs to run the server in the first place and keep the OS going, etc, and that will cause major lag and netty time-out.

Like was stated before there is no one single solution to this issue. You best chance at resolving this problem is to do further debugging on your map to see if you can find and resolve whatever it is that is making your server lag or time-out.

Heck, even just keeping Wi-Fi active on your router can enable unwanted hackers to break into your internet without your knowledge, causing just enough lag to force this time-out. Try disabling your Wi-Fi on your router maybe? I have a million suggestions to this problem.

You discuss the issue on a server, I am a user who can not play in Spanish servers because I will the problem, 4 exactly where had spent years playing and one day to another could not but because I can not do anything the server then takes me for this reason Internal Exception: io.netty.handler.timeout.ReadTimeoutException, bloqes can break the spawn, which is protected and that's strange, I have opened ports and searched thousands of possibilities and nothing, has nothing to do with animals or ports or anything my problem, what I do in the video is what really happens to me

https://www.youtube.com/watch?v=qcW-BqT32GM

You've helped confirm what I've discovered in the last few hours.

Even though the server computer should have more than enough ram to accommodate 2GB, the threshold of mobs that causes the error is much higher if I'm only setting the server to 1GB (causing MUCH less errors).

So thankfully, I feel like I've solved our servers issue. Hopefully that helps someone else, I haven't seen "lowering your RAM" be a solution anywhere before.

Thanks man

The base 1.8 vanilla server had 2GB set for the vanilla 1.8, I bumped it to 3GB for now, just to clarify 1 thing, the map was created in the first 1.8 Pre-Release (the PR1) we had a map before in the 1.8 snapshots but we stopped playing it around 14W21B and played a lot on a modded 1.7.10 and that is when the error happened 2-3 times max in more than 2 months of playing. Now we decided to create a brand new map in the 1.8 and since we couldn't wait for the release, we choose to start it in the pre-release which is normally not a problem at all. I don't think corrupted chunks could be the problem since I didn't experience this problem for 2 days in a row, but now that I'm building a fully automatic xp mob spawner, I'm getting worried that I could have problems when there's a lot of mobs in the spawner. Server has 8GB installed and working (64 bits OS) and I did a bunch of ram tests to make sure the ram wasn't a problem, the test passed 100% for 2 nights in a row, so I think the ram is out of the problem. I'm suspecting there's a problem with the entity and the way server does prioritize entities instead of the players, this might be what they need to fix.

Well, indeed there seem to be many reasons for this error message to appear. However, I do agree with Kyle Lane that something must have changed in 1.8, since I previously did not get this error message at all.
Furthermore, I would concloud that in my case the error is on the client side, since my friend, who is connected to my server via the internet, does not experience this problem. So I would rule out a corrupted map, too many mobs/animals, a crappy server and problems with the ISP. Is this conclusion reasonable?

I found out, that if I run the client on Windows, I don't get this error message. It only happens if I play minecraft on Linux (debian wheezy). However, I get a higher fps and smoother overall graphics experience on Linux.

@@unknown Regarding the RAM issue:
When things inprove because you give it less ram, there are usually one of two reasons for this error to occur.
1.) Your garbage collection is taking to long and since it usually happens when you move between areas (and thus load lots of new stuff), you will have heavy load already meaning that the garbage collection just becomes the tip of the iceberg.
When you lower your memory size the garbage collection
A better garbage collector (like G1 that I described in some previous post) might help in this case.
2.) You might have put it to close to the maximum ram your server/computer can spare, leading to your virtual memory using the harddrive as if it would have been RAM.
In this case a different garbage collector might help to crash it less often, but you should still dedicate less memory.

I am also experiencing this problem on Minecraft Realms, 1.8. No other players are on my server, seems to be happening in clusters. I'm unable to join the server I'm paying for from Mojang, for hours. Then suddenly it will work. I'm on Mac OSX 10.9.4.

Guess what, since now we know it does also happen on realms which clearly rules out any problems that would be linked to Internet or the specs of our servers, I'm more than certain they will solve it for the Realms really quickly, they care about their paying customers but won't care at all about the other users.

McDodge your logic is flawed but no point in arguing since I agree that 1.8 need to go back into beta. There just isn't enough stability or new features/content in 1.8 to justify it's release. But I guess that's just my opinion as a gamer and developer.

Why doesn't people read comments before posting?
This can be caused by 100 different things. Here are some examples... (Not all ofc)
Network problems like: Internet connection problems router/firewall problems (like port forward or whatever).
Memory problems like: Garbage collection problems, to little memory on the computer or to much memory allocated to the program and so on.
Processor problems: Processor cant handle the game fast enough.

This problem is not directly a cause of the game itself, so Mojang are not going to fix this time out exception. Changing the way that works would be against any common sense.
If you think about it for a while...
If an airbag on your car gets activated, you might understand that there is a reason for it. When that truck ran in to you, it was a response to that... Going to complain to the car manufacturer about it getting in your face would just be stupid, since that is what it is supposed to do.
The car manufacturer wont try to go in to details on what kind of car it was that hit you or how often you drive around in your car drunk. Thats not their thing to do. Also there are so many situations where the airbag can get activated, so for someone who does not know what an airbag is, it might seem quite random, and always in connection with something bad happening (like a car crash).
If you then go to a car dealer and he says "Well were you crashing your car?" and you say: Well yes.. But that never happend before I upgraded to the new nitro booster that is supposed to let me go faster.

So.. What was the point of that example?

Well.. Complaining about a time out exception in itself is not going to solve anything.
What you might want to do is to try and figure out what the real problem is instead.

For the people that say: Well this did not happen before 1.8:
1.8 requires a lot more of the system, both on the server and the client than 1.7 did. Of course you will start seeing this happening for the first time after an update.

Back to the car example.. If you have slippery tires on your car, and you upgrade it to go faster, you might just go fast enough to lose the grip in a corner and crash your car. Instead of complaining about the airbag.. Go complain about the tires... You might have had the same tires before, but since you could not go as fast with the car before, you never lost your grip on the road.

So.. FIRST: check EVERYTHING on your end.. Then try to figure out what causes the game to get a time out.
I mean it could be something like these two:

• MC-17630

• MC-58120
  (I dont know if these two could be the cause... I am just giving examples of things to check instead of complaining about a time out exception.)

Edit:
I have tried to help people here before, but since there are like 100 causes that it can be it is quite hard when people try one thing and then go back to saying: "This is not a problem on my end".
I mean you need to understand EVERY single possible issue that can cause this and try them before knowing that it is not your end.
Just updating java from java 6 to java 7 and implementing G1 (as I wrote about before) might not be a solution for YOU.. But that is an EASY solution if it is the garbage collection that is the problem.. If its not, then you need to CONTINUE to figure out what it is. Not just stopping and go complain here...

This problem is not directly a cause of the game itself, so Mojang are not going to fix this time out exception. Changing the way that works would be against any common sense.

@unknown, I understand why you are saying that, but this could be fixed at some point. As Grum states above:

I think there might be two issues at hand, one is that the server can get too busy to send you any data for some period of time (causing a timeout) and the other is that the connection you have to the server is so bad that there is no data for some period of time (causing the timeout). Neither is a 'real' bug, but we might be able to somehow fix the first issue.

@unknown Yes, but as he is saying.. This is not a bug.
The solutions would be to optimize the game in general. And then it is better that people understand that writing anything here wont solve the real bugs that are causing the server to get to busy.

I mean just to give the example of the pathfinding algorithm. It is crazy in the way it is implemented now, and can totally stop a server basically. No amount of cores and multithreading will solve for a bad implementation of an algorithm. So if people want the server to be smoother, they should focus on things like MC-17630 instead and upvote that.

Solving the problems with the bad algorithms would solve so many of the problems... Like choppy horse riding, beacons lagging, the sky ticking backwards, a minecraft day taking to long, spawnrate beeing low/slow, mobs beeing slow, blocks popping back up... and so on.. I could go on forever..

This problem in this thread can however be caused by a lot of other things aswell, and they are totally out of mojangs control.
They cant fix your router port forwarding to be correct for example.

IF people think that it is something caused by a bad code, then they should figure out what and post in those bugreports instead of trying here.. This thread basically says: "Something is wrong, probably on my own end, but it might be something that is caused by a bad code.. Please fix"
How usefull is that tbh?

I mean the point of this place should be to get minecraft to be better, right? And I dont see how any of this "something is wrong" talk is going to achieve that.

The problem is not that Mojang does not want to fix those issues, but every issue that has an incredibly long list of affected versions is just really hard to fix, and would sometimes even require a major internal overhaul. As not a single game developing company constantly does major internal overhauls, they focus on adding new content to satisfy player as long as the bugs are not fixed yet. This is also one of those bugs, and yes, I do know that Grum only said to be fixing a single cause of this bug. However, the cause he wants to fix is the only one they can change, so they are doing their best. Note that with "issues" and "bugs" I also mean performance issues.

Pierre,

I appreciate where you're coming from on this, but the problem is so many users aren't sophisticated enough to know what's happening when they get this error message. All they know is the game stops working and something incomprehensible pops on the screen. Your analogy to the car is flawed in that the majority of car users can identify when they've been in a wreck. A better analogy is the car simply stops running, an ambiguous light appears on the dashboard, there is no reference to this light anywhere in the owner's manual, and the car won't run again after that. Most peoples' next move is to take the car to someone who can fix it. In the case of a car, that's a mechanic, but in the case of a game, who do you take it to?

I agree, it's not a 'bug' but for a typical, unsophisticated user, it's simply the game ceasing to work, which to them is synonymous with 'bug.'

Maybe the 'bug' should be that io.netty.handler.timeout.ReadTimeoutException fails to provide meaningful error message to the player. I don't know enough to know if Mojang can edit this screen, but something along the lines of: "OH NO! Minecraft has lost communication with the server! Please check your network connection or contact your server administrator."

I used to have this problem back when chicken jockeys were causing chickens to live in dark places, laying eggs for zombies to pick up and never despawn. My friend who hosted the server couldn't find the root of why the server couldn't keep up with Minecraft, either. We think it just had something to do with the zombie pathing algorithm running amok and since we systematically cleared out the zombies, it hasn't been so bad in a while.

But I, as a relatively ignorant player, see this as a game flaw too. Can there not be some sort of fail safe put in place for when the server can't keep up enough to avoid a timeout? I can understand if the issue is in the player's connection, but if the game starts trying to run faster than the system running it, what's supposed to happen? And shouldn't there be a mechanism for recovery? Many people find that they alone can no longer log back onto a server, EVER. Shouldn't the server be able to drop them, recover, then let them back on at some point in time? It seems (to me, again, pretty ignorant, but just thinking logically) that this is a flaw in the way that the game handles itself.

Can someone explain where I'm off base?

@unknown, of course they can add something like that. But they won't, because it's an incredible amount of work, and most people aren't sophisticated enough to use it, as you already said. But you must not think that Mojang does not pay attention to stuff like that. Their rule is just making sure that the bug isn't there in the first place.

So that means for now, all XP farms (mine is a standard skeleton one, if I get more than 40-50 skeleton waiting, I get kicked out with that damn Io.netty error (tested on my secondary machine wired to a simple switch to rule out ISP or router problems), got the same build in a 1.7.10 test server I have right here on my secondary machine too, I get 160 mobs waiting for me and absolutely no problems except really low FPS of course) and that's not even counting the 60-70 cows that are on top of the spawner in that world, so now all villager breeders and all contraptions with a lot of mobs in them are now officially impossible to build because of this bug, if they can't fix it, I'm quitting Minecraft, I love to build crazy mob farms, villager markets and such, if I can't do it anymore, what is the point of playing this game.

How would you explain that the same exact build never ever caused any problems in a 1.7.10 server and now I get kicked out with the same thing in 1.8

Ok. Sorry for yesterdays rant. I was just tired and got a bit frustrated with people not reading and understanding. 😉
I understand that this is not natural for just any user.. So I will just start to help out again.

Instead of trying to make people understand what might be the causes for this, I will try to make a tutorial/walkthrough with anything and everything that I can come up with that can help to solve this issue. I will probably post this on my blog once its done and can link it here so that people can get the help. The reason I wont post it directly here is that posts seems to get lost, and its easier to just reply with a link to someone new than to rewrite everything or make people read through and find the old posts in this thread.

I will post again here when (and if) I make that tutorial.

Here's a question, could Max Tick Time have any affect on this situation? I remember changing that in my server properties a while back, but looking back I didn't really understand what that setting does and can't find a good explanation online.

Can anyone elaborate?

Yup Server tick time is probably the culprit here, I've examinated my server.properties files closely and I didn't have it on my 14w21b and also not in my 1.7.10 server, I've seen on a topic that disabling it could solve this issue so put it to -1 and it should be disabled, trying it myself, will report back if it works.

@unknown and @unknown, the "max-tick-time" option is for Watchdog, which shuts down your server if it is lagging. You can look at MC-63590 for more info, but it is probably not related to this issue.

This might be an issue with redstone, most people here are saying that they have automatic farms. I just got disconnected after lagging a bit and we have a redstone clock running to change the scoreboard.
[13:05:00] [Server thread/INFO]: [@: Set the display objective in slot 'sidebar' to 'StoneMined']
[13:05:13] [Server thread/INFO]: [@: Set the display objective in slot 'sidebar' to 'DiamondsMined']
[13:05:26] [Server thread/INFO]: [@: Set the display objective in slot 'sidebar' to 'StoneMined']
[13:05:56] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 26467ms behind, skipping 529 tick(s)
[13:05:56] [Server thread/INFO]: ObsidianMinor lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}
[13:05:56] [Server thread/INFO]: ObsidianMinor left the game

Can confirm that disabling the watch dog doesn't solve the problem totally, and its sure to be related to entities somehow, I now have a spider string farm and I get disconnected because of the spider jockey didn't get killed by the system (I will take care of this now that I know it can cause problems but that is another urrelated story)

Just something that people might want to check:
On your server, make sure that your "view-distance" in the server properties file is not set to high.
The maximum view distance changed to 32 in 1.8 so it might be that you have gotten that in there for some reason. A value of 10 should be good enough (around 160 blocks away in any direction from the player).

I am not 100% sure about this, but the difference between having this set 10 and having this set to 32 should be around 35 times more chunks being loaded around every player for your server.. (I have not checked the code on this though, so I can not be 100% sure)

I've never ever touched to the view distance in my server.properties file, I did it once while playing modded and settled it to 5 and the map wasn't complete on FTB so I switched it back to 10, I didn't see any improvments from touching this.

@Pierre Waldén: You seem to be pretty familiar with the Minecraft software. Do you know, what happens (on the side of the client) when one goes through a nether portal or tries to log on to the server? I had some time to do some testing in the last days and here are my observations:

• A friend of mine who is connected over the internet to my server (while I am connected to my server via a single cable and switch since my server is in my room)

• Unlike others, I don't suddenly get kicked off the server. I can play as long as I want until I decide to go through a nether portal

• Once connection is lost, any attempt to reconnect without restarting the client fails

• If I log on to my server and disconnect immediately after successful login, I can't login again. I have to restart my minecraft client

• When I start a world in single player mode and then decide to play in multiplayer mode, I can't connect. I get another error message (connection reset by peer). I have to restart the client to log on to my server

• When playing minecraft, my CPU (Intel core i3, 2x2,5 GHz) on my computer which runs the Minecraft client is at about 30-40% load. However, if I go through the nether portal (or try to reconnect without restarting the client) one of the CPU gets stuck at 100% until I lose my connection

• The timeout exception only happens when playing under Linux (debain 7.0 wheezy). Under windows (same computer) the problem does not happen. However, I get more frames per second when playing under Linux, therefore I prefer Linux

• The viewing distance on my server is set to 10. In general, All the server settings (except for the difficulty, which I manually set to 2 = normal) are default values.

I would appreciate any help and suggestions where to look further or which tests to conduct in order to isolate or even fix the problem

You need to run the server and client in a debug environment to see what breaks. Looking for signs "in-game" won't solve the issue.

Just to let everyone know.. This post might be considered a bit of topic, since it is neither containing any solution to this problem, nor give any new information regarding it. However, it might be something interesting to read for some of you and the reason I will even bother to write it is that I beleve that the more knowledge people have about anything, the easier it will be to figure out a solution on their own. (I dont know) If you dont like that, stop reading now! (You might learn something)

@unknown I am a regular user and Minecraft player like anyone else here, so I would not say that I am familiar with the Minecraft software specifically. (Even if I have read most of the code) However this issue is not specific to Minecraft. All I have is a general knowledge of computers and the stuff that I have learned both as a Java programmer and from courses available to anyone at the university. You should consider me as any other user and all I can do regarding this is to try to give you some hints.

Regarding what you have written here. It is good that you give information like this, since it is easier to troubleshoot the more information you have.
The question your have about what happens when you go through to the nether might not help you so much to solve your problem (as @unknown mentioned), but it might help you get some enlightenment or atleast give you some answers to what you are thinking about. 😉 First thing that might be of interest is that the server will have to send you all the information about the area in question, but this will be done when the server got "time" to do so. It can not send anything that it havnen't loaded or calculated itself yet. So if the server can't handle getting anything done, then it wont be able to send you anything in the same way that there is no point in sending an e-mail before you are done writing it.

Anyway.. Back to the question about the nether. Basically what happens is, (to simplify it a lot) that the server loads everything for the chunks close to you in the nether from disk to the memory. Depending a bit on where exactly that is it might need to read from as much as 4 different files (each containing stored chunks). The server will then try to check the state of everything there (so that nothing is wrong basically). If the mobcap is not met, the server will at some point after this start trying to spawn mobs during available gameticks. If the area in the nether is not explored it will, instead of loading it from disk, start generating it so that you have somewhere to stand when you get there. Somethin important to note is that this is NOT what is shown on your screen. It wont load any graphics or anything like that. Only data that tells the server what is where.
During this time the server might not be able to keep up with producing 20 ticks/second, but will instead que up some of what is happening for when the server have resources again. (This is one of the reasons why things might seem to speed up right after it have lagged a lot) If it takes to long, the ticks will be skipped.
After a while (usually around a minute), the server will start unloading your chunks in the overworld. This also uses a lot resources, but not as much as loading them.
Since the mob cap will change on each load/unload of chunks that contain mobs, new mobs will be generated as often as it can when the mob cap is not met.

Since the memory needed for having both the data from the old chunks and the new chunks loaded in memory at the same time is more than just having one area loaded, this might cause a garbage collection from your memory. If this happens a total stop usually happens (depending on what garbage collector you use). If a full collection happens this might take quite a long time. (To have a garbage collection here is not something desired and in most cases preventable in one way or another.)

When the server have resources to do so, it will start sending information to your computer, and if it have been unable to send information to anyone else online during the loading, this will happen at the same time. The information sent to the other players are probably tiny in comparison to what the person going through the portal needs to get. (For other players, this might lead to symptoms like blocks mined reappearing and so on if the server is behind.)

When the client gets the new data it will first be put in to memory, and then the client will start processing the data and then try to render everything for you.
If you are really unlucky, this might also cause a garbage collection, but this time on the client. (Basically: Lots of changes and new stuff to put in to memory --> Space needed --> garbage collection if memory is not sufficient.)

The explanation above is a bit simplified and probably not 100% correct, but will give you a general Idea of what is happening.

I will try to go on to talk a bit about memory in general. (Nothing to do with your question about Minecraft or portals) The memory you have available to use is not the same as the amount of "RAM" you have. That is just one part of the memory that your computer can use. There are several stages of "memory" for a computer, and it is in theory possible to tell a program that it can use lets say 8GB on a (64 bit) computer even if it only got 4GB ram without the program crashing. This is due to the way VM works. ( http://en.wikipedia.org/wiki/Virtual_memory ) The memory however will behave differently depending on how much you use. There are a lot of things that comes in to play, with page tables, pages and so on, but to understand this, you should probably take a course in computer architecture or something like that at the university and not read about it here. 😉 But basically there are several different places where stuff can be stored: Cache (small and super fast), Ram (Large and somewhat slow), Physical storage (Super large and super slow). So if your computer tries to use the disk as ram, I guess you can imagine how slow that is?

Another thing that is important to understand is that the processor of a computer often needs to "wait" for other things before it can go on. Processors now days will try to go on doing "as much as it can" while waiting, but in general, if something needs to be gotten from disk for example, this will take a LOOOONG time and the processor will not be able to do much in the meanwhile.

Knowing all this, you might understand that following the advice: "Give Minecraft more RAM" might not be the best thing to do always, since it can actually slow everything down for you.
Not only by using the disk, but also the garbage collections will take longer, since the garbage collector needs to deal with more data when this happens.

Giving minecraft the "right amount of RAM" is probably a better advice.

Enough about this now..

I sugest that if you want to understand stuff like this for real, you should take a course. To make it easy for you I went ahead and found a youtube channel with lectures if you are interested: https://www.youtube.com/channel/UCzf_XjIoKSf4Ve2fH7xn-3A That channel should probably cover the basics about VM, how processors work and so on.

Before ending this post I feel that I should give you something real. There are things that might give you some information to go forward in your quest:

• While being in the area that causes you to get the time out: Force a crash.

• On the server: log when full garbage collections are happening. (See java switches documentation)

• If you can't understand the logs yourself, post crash and server logs somewhere and ask someone to help you.

@unknown

How do I unsubscribe to this thread?

Up to the right on the page you press "Stop watching this issue"

MC-72222 same problem

Pierre Waldén, thanks for your detailed comment! I just did some testing again:

• I tried giving minecraft (client) less memory. Default value set by the launcher was 1GB and I tried 512MB and 256MB. Result was the same - when I go through the nether portal, I get the timeout error.

• RAM on server: My server has 12 GB of RAM - of those during normal operation approx 3-4 GB are used. The minecraft server is allowed to use up to 4 GB of RAM, but usually only uses a few 100 MB. At no time the server uses space on the hard drive as RAM.

• RAM on client: My client has 4 GB of RAM. When playing minecraft, approx 1.5 GB are used and also at no time space on the hard drive is used as RAM

• As I already stated, the problem does not occur when playing under windows 8. I just tried again and I can go through the nether portal without any problem. The nether appears almost immediately.

I forced a crash (using F3+C) when playing under linux (debian wheezy) and attached the crash report. I didn't find anything that immediately caught my attention. However, I also don't really know what to look for.

I didn't find the java switch which forces the server to log a full garbage collection. However, since the timeout problem does not happen when I play in windows 8 (and my friend, who plays on a Macbook with MacOS, also does not experience the timeout problem), I would say that the server is okay. Should I still force the server to log a full garbage collection? If yes, what is the right java switch?

And how do I run minecraft in a debug environment? I searched for a debug mode, but only got the mode in which the world consists of every type of block in every possible mode. But this sure is not the kind of debug mode I am looking for?

@unknown: I don't have that much time to answer right now, but OpenJDK 6 is a bad Idea for Minecraft tbh.
You should start by getting something else and come back.
In debian wheezy you will probably have to get some new repository, but there are a lot of useful info on how to do that if you google it.
My personal choice would have been either the latest JDK 7 or 8 from oracle.

Also I do not think that you should bother to much about memory/garbage collection from the info you gave in the last post. But of course you could try something like G1GC once you have installed a new Java if you like to try it. I don't think that the GC is the problem in your case though.

So.. Start with getting a new Java version and get back after that.

I think I have solved the problem, at least what the problem was for me.

in my task manager it was showing I was running minecraft on 64 bit but on my server it was only running 32 bit (x86 to be exact) I uninstalled the 32 bit Java and rerouted my run.bat file to point to the 64 bit version and viola I have been on my server now for almost three hours with max settings and no problems what so ever.

I did also clear my cache in the command prompt (run as administrator) and type "netsh winsock reset" it didn't work for me but it may for you all. as I said the thing that did the trick was running the server on the same java platform as minecraft. so you may have to look into that because this is what fixed it for me.

For myself, I'm just going to cancel Realms and go back to playing on the LAN, so much for opening my boys' games up to their friends, it's too frustrating and I don't want to bother with figuring out which JAVA each boy is using let alone those of their friends.

Got it on LAN too. Sometimes i can not log in but others are on my server and its running. Both same java. But it happened more often to players with internet connection. And different systems.

I've been fiddling with this issue on my server as well, and I can confirm that swapping x64/x86, Java 7/Java 8, or JRE/JDK does not seem to fix the issue. I have two friends in particular that have this issue about twice a night, but the other 5 or so online will not have any issues until the 2 others join, and then everyone is hit with massive lag.

Server reboots fix the issue temporarily, but I'm not always around to reboot things for them. This issue is causing a lot of problems for our small group of friends. Really hope someone gets around to fixing it soon, or providing a valid work around.

As another side note, memory allocation to the server doesn't fix it either. I've been playing around with the java flags on server start, and none of them seem to help either (either with absolutely nothing or -Xmn1G -Xss4M -Xmx2G -Xms2G -jar minecraft_server.1.8.jar -d64 -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=8 -XX:+AggressiveOpts -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+UseFastAccessorMethods -XX:+OptimizeStringConcat -XX:+UseBiasedLocking -Xincgc -XX:MaxGCPauseMillis=10 -XX:SoftRefLRUPolicyMSPerMB=10000 -XX:+CMSParallelRemarkEnabled -Djava.net.preferIPv4Stack=true). I'd gladly test out anyone else's ideas as I myself have ran out.

I'm not trying to start anything I didn't say it was a fix for everyone... I was only stating what worked for myself and my friends, swapping out the java platform 64 for 86 worked for us, we no longer get these issues, so while you can confirm it didn't work for you and your friends, it may/might work for someone else, I am just simply stating what worked for me.

however, I can add to my note that out of my friends and I, I was the only one getting the problem and I was running the server on the same computer as the program. so while they had no problems (both running minecraft on 64 bit I might add) I had this problem, once I swapped the 32 bit server for the 64 bit I no longer had the problem either.

I'm not saying it won't be fixed, but I really doubt they will ever work on this special issue since its not really a bug, we can only hope they will do something about this, but I really think they don't really care about this one. No one was ever affected to the issue and this problem is really old from pre MC1,7, we're now in MC1.8 if they had any intentions of fixing it, it would have been done, seriously, maybe they work on it but its not one of their top priority also.

Well I don't understand what you're saying. I had my complaint closed as a repeat and I was moved into this thread, but our complaint had zero to do with the version of MC. I had updated, fresh vanilla MC on both computers, was trying to play with Realms to try it out and it was disastrous, constantly kicking out whichever kid wanted to play on the server. That does happen once in a while in multiplayer too but nothing like this, it was basically unplayable.

The problem is this error appears for multiple issues. Having too many mobs causes this and there was a bug fixed that was duplicating mobs en masse in one of the snapshots. The defect causing this error for me when I first joined this thread was also fixed (.dat file issue). Slow connections, java versions, and more also cause this and people in this thread have found solutions for whatever caused this error for them. As long as unrelated issues keep getting added to this thread due to having the same error message this will never be fully fixed. Don't think however that nothing will get fixed because we've already seen many causes for this error fixed in the past.

In my case, this isn't fixed, I can't use any mob spawner for XP grinding at all without getting kicked out when there's more than 40-50 mobs waiting, which is quite a challenge, I must stay in front of my PC with the game open at all time if I want to grind some XP, can't go AFK anymore, I have an auto-fish farm that works overnight and get me some XP, but its a lot less efficient. Hope for a fix, but I think I'm going to wait a long time for this one to be fixed.

it doesn't happen on my windows 8 pc but it does on my macbook pro. It isn't related with the internet because i've tried in several networks and it wont connect to any server

EDIT: Also occurs on ubuntu and on Minecraft 1.8

happens to me. my windows 8.1 computer gets this error quite frequently (about 15-30 times a week) while my windows 7 laptop has never gotten this error. I have tested this with an ethernet connection.

Starting to think this could be different depending on the exact CPU the computer does run on, since they added threaded stuff and the mob AI is on a separate thread now, perhaps the model of CPU used can cause this issue for some people, There's so many CPU, dual core, quad core CoreI3, CoreI5, CoreI7 and that's just for Intel cause I don't know that much about AMD CPU, maybe this is different depending on the exact model of CPU, my PC use a Intel Core2Quad Q9400 at 2.6GHZ

This is obviously an ongoing issue that has more than one cause, as my friends often experience this while trying to connect to my server. It started sometime in the mid-2014 1.8 snapshots. Also, something I find interesting is it allows them in for a little while, but they can't break/place blocks, type messages, or do any action besides take damage it seems, and then it kicks them off after 30 seconds – 2 minutes. I've also been kicked off as well.

@unknown: Seems like you are either pushing your server to the limit or your network (probably the network in your case).
Check so that no one on your network is downloading torrents, watching youtube/netflix, or anything else like that.
Knowing nothing about your setup or when exactly it happens for you and your friends, it is hard however to say for sure what your problem is.

I'll look into that possibility! Is it possible it's caused by allocation of too much RAM?

@unknown:
Yes allocation of to much ram will cause all kinds of mess, since it will use your harddrive as RAM instead. (And I guess you can imagine how slow that is?)

One cause of this error is discussed in this thread here with a possible fix for non-UNIX users.

http://www.minecraftforum.net/forums/support/server-support/2205991-1-8-server-crashing-skipping-ticks

You will see 4-5 maybe more tick skipping errors in the server logs back to back and then everyone will get kicked with the io.netty error. Sometimes it will even force the server to restart. This is one of the somewhat common cases with io.netty errors since 1.8

This fixed only the cpu usage Problem, but netty.io, scipping ticks and crashes still appear. sure Server runs better.

Getting same error as everyone else. Network activity is normal for 30-60 seconds and then just cuts off.

EDIT (more descriptive):

Did not occur until the 1.8 upgrade. was not occurring while running 1.7.9

I can log on to the multiplayer server, but can only interact with doors and smash blocks. Can not interact with chests, furnaces or bed, can't pick items up. After 15 seconds or so I will be transported back to my starting location. I might be returned to the starting location 2 or 3 times before the error occurs. Maybe a total of one minute, error occurs 100% of the time when attempting to play in multiplayer mode.

Network activity appears normal and then drops to zero and the error generates in about ten seconds after the network activity cuts out.

Activity monitor shows Minecraft CPU% as high as 319% in single player mode. Minecraft is using about 820Mb of memory.

I see the following message in the Minecraft launcher during single player mode.

[20:30:08] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 3747ms behind, skipping 74 tick(s)
[20:30:10] [Chunk Batcher 0/WARN]: Needed to grow BufferBuilder buffer: Old size 524288 bytes, new size 2621440 bytes.

iMac 3.2 HHz Intel Core i3
4 GB memory
OSX 10.7.5

I run a Vanilla SMP server on an HP Desktop:
Windows 7 Pro SP1
Java 8_25 (64Bit loaded from java.com offline version)
vanilla 1.8 (never modded or messed with)
4GB RAM
Intel Core2Quad Q8200 (2.33GHz)

This machine is dedicated to this server only and is used only for this purpose.

Internet connection is 75MBs up and down via Fiber.
Server directly connected to Linksys Gigabit router with high priority set to both port 25565 and the MAC address of the server.

Here's the key part of my batch file to start the server:

java.exe -Xmx2048M -Xms2048M -jar minecraft_server.jar nogui

And my Server.properties file is:

#Minecraft server properties
#Mon Oct 27 23:44:44 EDT 2014
generator-settings=
op-permission-level=4
resource-pack-hash=
allow-nether=true
level-name=world
enable-query=false
allow-flight=false
announce-player-achievements=true
server-port=25565
max-world-size=29999984
level-type=DEFAULT
enable-rcon=false
force-gamemode=false
level-seed=
server-ip=
network-compression-threshold=256
max-build-height=256
spawn-npcs=true
white-list=true
spawn-animals=true
snooper-enabled=false
online-mode=true
resource-pack=
pvp=true
difficulty=3
enable-command-block=false
player-idle-timeout=0
gamemode=0
max-players=8
max-tick-time=60000
spawn-monsters=true
view-distance=10
generate-structures=true
spawn-protection=16
motd=Corrupt again!!!! I hate this!! Backup restored AGAIN!

I defrag often, update always, and run diskchecks monthly. I've never experienced any problems running a server in 2 years and 1.8 was the first time I've had these problems.

Problems:
People unable to stay logged into the server. Client get's kicked with IO.Netty errors and their avatar stays in game. Performing 'list' command at console shows user still logged in. I am unable to 'kick' them. If they log in again, a second instance of thier avatar shows and a second user with the same username shows on the list. User is disconnected from the server within a minute or two at most.

I haven't tried deleting the user UUID (which deletes their inventory too, right?) but I have gone back to yesterday's backup and was able to get them back on. That causes us to lose a day's work and I'm losing users because of that.

Someone mentioned they have lots of animals spawned and when other users come near, this happens. That's exactly what happened last night to one of my users when he came near my farm. Lag, lag and then he logged out and back in to try and alleviate the problem but was then 'ghosted' and kicked.

This time there were no errors posted on the console but I have seen many IO.Netty errors thrown when this has happened in the past. I will provide copies of any files any developer needs to help solve this problem. I have kept all logs and world files (including corrupt ones) just in case.

In testing with one affected user: He was able to connect to a second instance of a server (new world, separate port) on the same server with no issues but could not connect to the main server.
When he logged in and saw his ghost, he moved as far from the chunk he was in as possible, this took several login attempts. Once far away from the offending location, he was able to get back on. Whenever he moved back to that chunk, he was dumped from the game and given the netty io error.

Sometimes the server console shows the error, sometimes not.

I am available to send files as requested, I keep copies of everything, logs, world files, etc.

Please, dinnerbone kenobi, you are our only hope.

I have had this problem several months ago and it was when switching internet company, months that I could not play my favorite premium servers could not interact with blocks ...
Today they gave me a possible solution and I tried it and miraculously the program has helped me and now I can play normally, I leave the data to try it in the video you can see that it is
Good luck to all

http://youtu.be/GKfCIMRBaTU

This WTFast tool will NOT solve the Problem in an LAN-Environment with 3 GE-Switches from Client to Server, where the error sometimes occures. Programm is only free Trial.
I wait until the Server shows me not online, and after that, i can connect normaly. Teleporting affectet Players away solves also the Problem once.

Well, like everything, it takes who serves and who does not then leave it, I found it as soluciión able to play my favorite servers, for that is the test to see who does well, I poured me: P

This happens frequently on my mac. i found that everytime it occurs it coincides with System.gc() getting called.

here is some example jstat gccause output:

S0 S1 E O P YGC YGCT FGC FGCT GCT LGCC GCC
0.00 27.41 9.02 18.82 62.87 103 0.871 7 0.840 1.711 unknown GCCause No GC
0.00 27.41 20.41 18.82 62.87 103 0.871 7 0.840 1.711 unknown GCCause No GC
0.00 27.41 27.43 18.82 62.87 103 0.871 7 0.840 1.711 unknown GCCause No GC
0.00 27.41 39.29 18.82 62.87 103 0.871 7 0.840 1.711 unknown GCCause No GC
0.00 27.41 45.31 18.82 62.87 103 0.871 7 0.840 1.711 unknown GCCause No GC
0.00 27.41 48.32 18.82 62.87 103 0.871 7 0.840 1.711 unknown GCCause No GC
0.00 27.41 51.33 18.82 62.87 103 0.871 8 0.840 1.711 No GC System.gc()
0.00 27.41 51.33 18.82 62.87 103 0.871 8 0.840 1.711 No GC System.gc()
0.00 27.41 51.33 18.82 62.87 103 0.871 8 0.840 1.711 No GC System.gc()
0.00 27.41 51.33 18.82 62.87 103 0.871 8 0.840 1.711 No GC System.gc()
0.00 0.00 11.65 16.51 60.00 103 0.871 9 1.210 2.081 CMS Initial Mark No GC
0.00 0.00 11.65 16.51 60.00 103 0.871 9 1.210 2.081 CMS Initial Mark No GC
0.00 0.00 11.66 16.51 60.00 103 0.871 9 1.210 2.081 CMS Initial Mark No GC
0.00 0.00 11.66 16.51 60.00 103 0.871 9 1.210 2.081 CMS Initial Mark No GC
0.00 0.00 11.66 16.51 60.00 103 0.871 9 1.210 2.081 CMS Initial Mark No GC
0.00 0.00 11.66 16.51 60.00 103 0.871 9 1.210 2.081 CMS Initial Mark No GC

Not that I have anything immensely useful to report.

But my experience with this is using a local lan dedicated server for a 2 user multiplayer world (myself and my son).

The world was built with 1.7.10 and seemed to be operating fine. Upgraded the server to use 1.8 and copied the world over.

Now I receive the above message running on a Mac Book Pro over the wifi connection, while my son does not experience this using a hard wired PC (Windows 7).

If I move back to using 1.7.10 the issue disappears.

I thought maybe it had to do with enhanced resource requirements for the server (as it is an old machine with a single CPU and 1.5GB RAM). However as it never affects my son, this doesn't seem likely.

Next issue would be that I connect wirelessly, while he is wired to the LAN. This is possible, I have yet to try a wired connection to the LAN (I need to get a Thunderbolt to ethernet connector). So I will have to try this to confirm or rule it out.

In my case the load on the machine is low, the RAM allotted to java is large for 2 users (-Xms1024 -Xmx1024), and the network is a local LAN and therefore not affected by internet speeds.

But I am wondering if this is a catch-all warning, as it seems to be happening to a lot of people for a variety of reasons.

Getting this error when logging into a private server I have been playing on for months. Sometimes I get Connection lost: timed out and other time I get this error. My daughter in the same house on a 2nd laptop is getting the same errors. I can not connect to her LAN world but she can connect to my LAN world. Started yesterday after upgrading to 1.8.1.

My niece has restarted the private server several times but still have this error happening. I can log onto all other servers I have tried but still can't log into my daughters LAN world. My internet speed is pretty good ping 17 download 36mb upload 2mb.

Grum's comment (Ignore the title of the report; That's a different issue.).

Just in case anyone needs the server side of this here it is. http://pastebin.com/dqjT73ct

So, i have been reading every msg so far, to me it just seems like Mojang doesnt care, at all.. this bug have been here for far to long.
i got a friend who simply gave up because he couldnt stay on a server for like 1 min before getting the Error Msgs.
So there was no point playing minecraft.

You guys do realize this error message occurs for hundreds of different reasons right? Did you even read through the entire defect? Mojang has fixed a multitude of bugs causing this error. A lot of us no longer experience this error due to the fixes Mojang has implemented. If you do not have anything useful to contribute do not bother posting. Tons of people posting complaints and not staying on topic clutters the defect and makes even less likely any new issues will get resolved.

But still Joseph, i have been on countless sides whos talking about this problem, they all talk about either SPigot, or a minecraft version above 1.7.0 is the reason to the crashes. and since its a minecraft version that makes the problem, that shouldnt it be possible to fix it?

I run a 1.8.1 SMP world generated clean in 1.8.1, no mods (pure vanilla.) I have a Verizon Fios connection with 75Mbps up and 75Mbps down. I maintain the server on a Windows 7 pro 64 bit system with 4GB of RAM, the latest 64-bit JAVA and proper updates with no other software running on the server.

Several of my users, all with decent internet speeds of their own, have had this happen.
They are either outright disconnected or, mostly, they connect for a few seconds to one minute and are kicked with the io.netty error.

It seems that this happens mostly when the affected player comes near a location in the world where mass production of animals is being done. What I mean is player 1 will have a farm with 200 chickens in a 10x10 block pen and player 2 will approach within 100 blocks or so and then lag so badly that they disconnect. When reconnecting thereafter they get the error.

I have seen a player who experiences this error come into the game for the minute the game allows and then he moves away from the area and can thereafter eliminate the error.

In the other cases, I've deleted the affected player's world\playerdata\player.dat file and they are then able to return to the server (losing all their items).

This problem began to appear in our environment as of 1.8 but I think it has happened to others on previous versions.

My gut feeling is that it is related to sync issues in the io.netty 4.x handler but I am not a programmer.

I hope this description helps a coder who cares. If you have any questions, I'll be monitoring this thread.

Hi. I really appreciated Robert's comment, but I don't know how to reset my player data on the server I am experiencing glitches on. I have also noticed that even on my own server (A minecraft realm) I get the same error, and because minecraft realms helps you deal with no coding, I am left without any way to enjoy my server or others. I only recently contracted this "Disease" But I really need help fixing it. I'm just tired of constantly being logged off. Please help.

Also I would like to report that my crashes do not have the same message. They instead say: Internal exception: Java.io.ioeException: An established connection was aborted by the software in your host machine.

Same problem, I cannot open / join any LAN worlds, on minecraft 1.8.3 / 1.8.2.

I'm getting the netty error on my self-built server running Minecraft 1.7.10
When I connect, even if using the same PC to connect to the local machine I can play for maybe a minute, then I get the timeout error and the server stops responding and I have to force close it as the 'stop' command does nothing. Checking in task manager and the server does max out my CPU usage. I have it set to run only on two cores currently but even if I leave it to run on all four cores it stops around the 75-85% CPU usage!
I also keep getting the [19:16:48] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2998ms behind, skipping 59 tick(s) message, straight after starting up the server, before anybody has attempted to log on!

Its clear this bug is definitely not a small or isolated issue. I realize this is not a "support" forum. None the less it is where users can provide information regarding issues and they will inevitably also seek information. Is it too much to as for someone from Mojang to get on this thread and provide some feedback. I'm not talking about a "how to fix", just an acknowledgement of what this issue is and what they know so far and what is being done. I find the silence from them on this thread deafening.

Unfixable per Grum's comment from MC-66611:

That is how timeouts work, the server thinks you are still there until it doesn't anymore.

I've been frustrated with this issue for months. My specific symptom was randomly getting booted. No rhyme or reason.
After reading through much of this thread and a few other sources I decided to look into the priority settings for my router. Verizon Broadband.
I set a priority specifically for Minecraft to focus on Packets. Before I made the change I was getting booted every 5 minutes or less. After the change I haven't crashed once. Still holding my breath my so far so good.
Mac server. Running latest forge (had same issue with vanilla). Running it out of my home.
Verizon router M1424WR
Logged into my router. Went to Advanced / Traffic Priority. Set the following....

Source Address: Any
Destination Address: Any
Protocol: Minecraft (Selected from dropdown)
Operation
Priority: 7
Apply QoS on: Packet

I know many admins are running different equipment and some are renting servers so this won't really help you. But for you home hosts, look into Traffic Priority on your router. Will edit or post again if the problem comes back. But I would have expected serval 'crashes' by now.

Cheers. Good luck. Hope this helps someone.

I have the same problem on my server but it is spigot 1.8.8

All the users are kicked at the same time

This bug tracker is for vanilla Minecraft only. Spigot issues will have to be reported to spigot. Lots of things bring up this error message. Some are bugs, some are not. The original issue has long been fixed and this ticket is now a mess of other random issues. You would be better off reported new issues in their own tickets as this one will probably never get seriously looked at.

I found a fix that works for me

All I did was going to the metrics configuration and set it to opt out.

And this fixed it.

This Helped me

If you wish to disable Metrics, you can do so by opt-ing out, which you can do in the Metrics config file under /plugins/PluginMetrics/

Anyone getting this in the 1.9 snapshots? Or even in release 1.8.8?

Affects Version/s: Minecraft 1.11.2
Environment:
Java 8 update 131
Mac OS x 10.8.5

Description
My son (13 years old) bought Minecraft two weeks ago. After installing Minecraft the game did not open. There was something wrong with the launcher. Got that fixed looking for some help with google. I now go the the folder ' application support/minecraft'. And there i start the game with the launcher.jar. So far so good. I'm in Minecraft now. But...no matter which server is add, none of them is working. Can't connect with server: io.netty.channel.ConnectTimeOutException: connection time out:".
I've searched the internet for help. With no result. I don't know what to do. 24 euros is al lot of money for a boy of 13 years old. If somebody can help, that would be wonderful!

My issue is resolved, but i still don't know what to do!!

kind regards from Holland

My error report:
Couldn't connect to server
io.netty.channel.ConnectTimeoutException: connection timed out: 4.ip-192-99-213.net/192.99.213.4:25565
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe$1.run(AbstractNioChannel.java:213)
at io.netty.util.concurrent.PromiseTask$RunnableAdapter.call(PromiseTask.java:38)
at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:123)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:380)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:357)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
at java.lang.Thread.run(Thread.java:745)

THIS IS THE FIX:

i got this issue fixed by ringing my internet provider and asking them to
unblock port 25565 on there end

On Sun, Feb 8, 2015 at 4:28 PM, Joseph Meyers (JIRA) <[email protected]>
wrote:

> Joseph Meyers
> <https://bugs.mojang.com/secure/ViewProfile.jspa?name=sefjwm> commented
> on an issue Re: Internal Exception:
> io.netty.handler.timeout.ReadTimeoutException
> <https://bugs.mojang.com/browse/MC-34947>
>
> You guys do realize this error message occurs for hundreds of different
> reasons right? Did you even read through the entire defect? Mojang has
> fixed a multitude of bugs causing this error. A lot of us no longer
> experience this error due to the fixes Mojang has implemented. If you do
> not have anything useful to contribute do not bother posting. Tons of
> people posting complaints and not staying on topic clutters the defect and
> makes even less likely any new issues will get resolved.
> [image: Add Comment]
> <https://bugs.mojang.com/browse/MC-34947#add-comment> Add Comment
> <https://bugs.mojang.com/browse/MC-34947#add-comment>
> Minecraft <https://bugs.mojang.com/browse/MC> / [image: Bug]
> <https://bugs.mojang.com/browse/MC-34947> MC-34947
> <https://bugs.mojang.com/browse/MC-34947> Internal Exception:
> io.netty.handler.timeout.ReadTimeoutException
> <https://bugs.mojang.com/browse/MC-34947>
> I will get this error occasionally when trying to join a server:
> Internal Exception: io.netty.handler.timeout.ReadTimeoutException
>
> -EDIT: As seen on this post, it generally happens for people with worse
> connections, though I never got this error in previous versions.-
>
> EDIT: It has apparently been confirmed that even with faster internet
> speeds, the ...
> This message was sent by Atlassian JIRA (v6.1.6#6162-sha1:7af547c) [image:
> Atlassian logo]
>

According to duplicate bug reports, this bug affects up to Minecraft 1.12.

Does this still affect the current versions of Minecraft? (1.12.2, 1.13-pre3). If so, please update the ticket accordingly.

I can confirm me along with my friends have this issue with Minecraft 1.12.2.

We all have at least 50Mbps, 300Mbps, 100Mbps, and 1Gbps network connections.

This issue does not affect my friend who is in the Czech Republic with a 100Mbps connection connecting to my local server on a 300Mbps WAN connection, nor my friend in a neighboring state with a 300Mbps connection.
The issue however affects me (on a 1Gbps LAN connection to my server), my friend rarely who is on a 50Mbps connection in a neighboring state.

The server is hosted in the US and I connect to it via a 1Gbps LAN connection as stated before..

This seems to be an issue when we build too many mod-based structures around our bases..

Oddly it affects everyone differently as far as frequency goes.

I'm no longer able to connect, however all 3 of my friends who have a slower connection to the server can without timing out every time.

Coleton M:

The info you gave was good and might very well be the issue talked about here, but you kind of made it invalid by this statement:

"This seems to be an issue when we build too many mod-based structures around our bases.."

Is it possible for you to test using the same hardware, but with a vanilla server and vanilla clients?

I made an account just to thank you @meedie

A year later and it still works. Followed the steps to change Java, worked like a dream.
I run a server for my fiancee and I using Lapitos galacticraft mod pack, she was timing out and lagging constantly, I went through dozens of different fixes that sometimes made things worse.
Can't speak for everyone, but it's worth a shot. Worst case you've discovered the 3925th fix that doesn't work for you.

confirmed for 1.13.2

also having this issue with 1.13.2

confirmed for 1.14.4

Still in 1.15.2

Yeah this sucks.  I'm limited to about 20 seconds as well lol.  I've also read that this is basically an impossible fix for for people who ate limited to a Mobile Hotspot, also me oof.

These might help: [Havent helped me though]

-Allow Java Binary SE through Firewall

-Forward Port Number to 25655

-Try turning it on and off lol

Still happening on 1.15.2. can't possibly be Low Priority, c'mon Mojang. no point for me to play the game if you don't let me.

me too, 1.15.2 Forge LAN conection

1.15.2

I found my way to this post after my friend kept on being disconnected from my LAN world. After a little bit of digging in the end it turned out that I didn't have Java installed. After installing Java my friend is no longer getting kicked and everything is working as intended. Don't know the technical side of things and why this worked but I thought it would be worthwhile mentioning this in case others could also use this simple fix 🙂

Good luck!

1.15.2

So I may be a little late, but I did find a fix, for at least myself. After not being able to play for about 20 minutes, I checked firewall settings, and my "processes" in the task manager and it turned out I had a SECOND launcher open in the background, which presumably is trying to launch the game again, therefore giving the force close because the system is not technically allowed to let that happen. Again this fix worked for me, and hopefully you as well. I am also not a technical genius, it is just my interpretation on the matter.

I think this might be the fix for both Windows and Mac users. Here's the video tutorial by tech How. I'll simplify it here.

Windows
1. Go to your ipv4 setting (e.g. Control Panel>Network and Internet>Network and Sharing Centre>Connection:Your internet setting>Properties>Double-click "Internet Protocol Version 4")
3. Select "Use the following DNS server addresses"
4. Change the setting to "Preferred DNS server: 8.8.8.8" and "Alternate DNS server: 8.8.4.4"
5. Click "OK" and done!

Mac
1. Go to your ipv4 setting (e.g. System Preferences>Network>Advanced...>DNS)
2. Click the "+" to add "8.8.8.8" and "8.8.4.4" to both DNS servers (and Search Domain if not working)
3. Click "OK" and done!

I had the connection timed out issue on my friend's 1.12.2 forge modded server. I was often able to load 1 frame before the "Connection Timed Out" and get disconnected (or only "Disconnected", "netty.io...ReadTimeoutException", etc)
The video by tech How was for Windows but editing the dns setting also work on my macOS Big Sur 11.5.1. It took me hours to find the fix. I recommend installing the latest version of Java since I'm not sure if it's also part of the solution. Hopefully this works for whoever was having the same problem.