Constant teleporting between Nether and Overworld

Fixed in 15w43a (tested in a new created world)

Have you tested in a server? This bug has only ever happened to me on a server. However, testing is heavily imparied by MC-91043

Affects 15w43b, tested in a newly created world. Please reopen.

Affects 43b in SMP only.
Unable to reproduce in SSP.

Also this bug is the same as MC-89928 as about 50% of the time it follows the behaviour described there after the loop is broken.

[17:00:31] [Server thread/WARN]: Laney1 moved too quickly! 38.0,8.0,-256.7251175
901253
[17:00:33] [Server thread/WARN]: Can't keep up! Did the system time change, or i
s the server overloaded? Running 2034ms behind, skipping 40 tick(s)
[17:01:17] [Server thread/WARN]: Laney1 moved too quickly! -2.3938919758602393,-
43.0,773.2220083635249
[17:01:54] [Server thread/INFO]: Laney1 tried to swim in lava

Here is a log of the incident.

Can confirm it still happens in a freshly created 43b world, though it's somewhat fiddly. I tested with different worlds generated at different versions (some 43b, and some 42a and previous) in creative and survival, with varied results. It wasn't consistent, and sometimes worked without problems even on 42a generated worlds, but also sometimes seemed to depend on creative or survival. On a freshly created 43b world I can confirm I still got the bug while in creative, though survival seemed to work without problem as far as I could tell. More testing could prove otherwise.

Still occurs in 43b. More prevalent on Mac OS X rather than PC on same server.

In a fresh 43c single player world portals seem fine in survival, but in creative it's rarely giving me enough time to get out of the portal before it sends me back so I get stuck in an endless loop.

server play: survival 15w43c
go through the portal , take 1/2 heart damage coming out . and then get tossed back through and cop another 1/2 heart damage . eventually end up in a wall some where and die 😞

totally unplayable.

@@unknown: Please stop constantly editing your post. 13 people are receiving an email each time you do. The preview feature exists for a reason.

sorry just trying to give as much info as possible (and didn't notice the preview button BTW)

here's more info that I've been able to fathom

any lag from anywhere , eg: server having mobs to update in new area or internet lag , or computer lag on players end it happens.

I just removed some lag be closing some programs eg: web browser, email client, and rebooted my router to get the cleanest minimal lag. and still got the 1/2 heart damage going and coming back. but was able to move out of portal. So it looks like we need more time to exit. i haven't been able to ascertain why I'm getting getting 1/2 heart damage every time i go though it though there and back

once again sorry to all.
only trying to help,
hope this info helps

Can confirm on 43c

Workarounds I found:
1. Re-logging just ofter you are put into the new dimension usually cancels this bug, most likely by resetting the cheat detection.
2. Switching gamemode to spectator mode (if you have access to commands) will break you out of the loop too.

I had to disable the Nether on my family server for the time being. happens to everyone on my server using snapshot 43c (yes, I have a map backup without snapshots just in case). Seems to be Multiplayer only, I haven't had an issue in Single Player at all, but its both Creative mode or survival mode it doesn't matter. Endless teleporting loop, being snapped back into the portal after leaving it and immediately being ported to the other dimension. My brother and my friend both died of suffocation damage due to taking a small amount of damage every time and endless looping til death. Upon respawning back in, no items can be found in either dimension.

I want to know if there is some way to just disable the cheat protection. It's my server, and I'd rather have cheat protection broken (and thus disabled) than access to anywhere beyond the overworld broken.

@unknown as of now, no

I have so far not been able to reproduce in 15w44a. Can anyone confirm whether or not this is fixed?

MC-89928 is confirmed (end), so this is likely to still exist. However I am not inclined to update my server to a 2-hour-old snapshot.

15w44a still happend.
(Confirmed by me)

Still happening in 15w44b

Still happening in 15w45a.
Sometimes it seems fine and potentially fixed, but as time goes on it begins to manifest again more consistently. (Memory leak?)
It's often really bad in Creative Mode, but even in Survival it happens sometimes. And in Survival when it occurs, I often take a point of suffocation damage after being transferred to the Nether/Overworld.

The client is also lagging heavily behind the server as when I use /gamemode 3 in the console to escape the loop I continue looping for 2-3 tp "cycles".

Confirming this bug is affecting 15w45a

I switched my home server to allow nether to see if it was still effecting us, and it sadly is, so I have once again temporarily disabled the nether. My buddy gets caught in the loop and dies without fail if he tries to go to the nether.

I made a backup and switched maps to a new map (with a clean new SMP folder with all new files from the snapshot, not reusing any files from older worlds or snapshots), it still was an issue so my personal experience says it is not a save corruption issue.

Still an issue in 15w46a

Still having the issue in 15w46a.
The issue isn't as bad if the chunks around the portal are loaded, so maybe pre-loading chunks around the portal when it's used could be a solution? Or perhaps increasing the cooldown time for portal usage?

My experience with this bug as recently as 15w46a on Survival Multiplayer is that if you are alone on the server, it seems less liable to trigger while if there is another player, and if she is within load distance of your destination portal, the chances of replicating the bug become nearly certain.

It's become predictable enough that we can try to use the portal knowing another person is near the far end, experience a bounce at least 9/10 of the time, ask other person to briefly log out, then go through the portal with nearly 100% chance of success and let them know it's safe to log back in.

I do not think the cooldown time will (or certainly should!) make a difference since when the bug does not trigger — as should be the case — you can stand in side the portal blocks in the destination portal indefinitely and experience the visual warble effect and purple swirls but never travel through the portal again. What has to happen is that first you leave the portal blocks for at least one tick, then come back, and then there is a timeout.

I am not convinced that this cooldown mechanism is either broken or lagged. When I bounce back to source portal, it normally happens in less total time (several seconds less) than not bouncing, spending a split second leaving contact with portal blocks before re-establishing contact, and waiting for timeout to move me again. I am fairly certain the game is sending you back as some sort of a "last known good position" feature due to detecting your character "moving too quickly" instead.

View when first traveling through both sides of a portal.

I've noticed when traveling through the portal the chunks that load first aren't the chunks containing the nether portal. I wonder if they loaded first the player would be able to travel far enough outside of the portal to not be reset back to the portal position once the chunk finally loads causing the loop.

This has happened to me in singleplayer survival (14w46a). To try to stop the infinite looping, I held a directional button while the world was loading, to try to move out of the portal quickly enough to keep from teleporting back. When the world finally loaded, I had already fallen off the platform my portal was on, and I fell into lava and died. I think this means that the game starts (allowing the player to move, and the portal cooldown timer to start) before the dirt texture loading screen actually goes away.

I really think this bug is two separate problems. One being that portals don't require you to get out and back in to teleport you again. And the other being that the cooldown (and probably the rest of the game) starts before the loading screen goes away.

@Wyatt Jackson: but in the current iteration of the bug, I (and I would guess basically everyone else ever) have already tried holding a directional key from the moment the screen cuts away from the source dimension and begins the dirt texture loading screen. In my case, the entire layout of my nether portals supports this: both are in closed off rooms against a wall, coincidentally such that if you face the wall in one world you will be teleported into the other world facing the center of the room. So all I do is hold the forward key into the portal, taking me through the portal block until my nose is mashed against the wall and I continue holding. In cases where this bug bounces me back (in my case this is normally when another player is in the far dimension with chunks loaded) I land back in my source portal still grinding my nose against the wall. I never bounce twice or wind up in a "loop" as others here discuss, probably because there's never another player at both ends of the portal simultaneously.

If the bug does not bounce me back, then my key holding rockets me out of the destination portal at walking speed into the safe, closed in room on the other side. Again: basically only when no other player is nearby in the destination dimension.

This bug is still an issue in 15w47a. It happens to me no matter which way I go, and commands (such as /kill or /tp) don't take effect for a long while, even when inputting the commands into the server console.

This is another serious and annoying bug that has like others been well overlooked, despite being voted up etc and is more then a pain in 15w47a as well prev versions

Still in 15w47a.
(Update from previously made comments: I'm now fairly convinced this is related to the anti-cheat detection changes made since 15w41a.)
I've done some testing over the past 24+ hours on my server. Normally, the portal issue occurs within the first use or two of a portal and with near 100% reproduction rate. It has occurred every reboot with every snapshot update tried thus far.
I have now set allow-flight to true in server.properties and the issue has not occured since my last reboot (it's been several hours with many people going through portals frequently.) No one thus far has reported any portal bouncing since enabling allow-flight. Whether chunks are loaded or not seems to be irrelevant as both loaded and unloaded areas have seen this resolved since disabling the anti-flight on the server.
I'm guessing the anti-cheat detection is getting false positives of "flight" when portals are used and tries to push people back to their last "good" position and thus causing the portals to bounce people repeatedly.

Can anyone else confirm/deny these results?

@@unknown: our affected world has always had allow-flight enabled.

same bug? MC-86850

Allowing Flight hasnt solved this issue, would be great if it did, but sadly not

Update: the issue seemed to be fixed for me for awhile but then started again randomly and worse than ever. I'm guessing it's a combination of network lag and chunk loading/unloading for the most part but it's not always consistent to be absolutely sure.

This is still in 15w47b in a Creative server, often going either way (to Nether from overworld or back). Sometimes I'm in one place long enough to get to the esc menu and disconnect, but others I've had to externally close Minecraft.

Cannot confirm for single player.

Still a nuisance in 47c and is very much quite the troublesome glitch, even worse if you happen to attempt to go through the portal in Creative.

I've also noticed on Console if the loop gets bad an a player disconnects from the game part way through overworld an nether or visa versa, it can cause the client to Ghost on the server, showing the client as logged in when in fact they have disconnected with the console spamming the below:

8:19:30 PM CONSOLE: 2015 10:19:22 AM io.netty.channel.AbstractChannelHandlerContext invokeExceptionCaught
8:19:30 PM CONSOLE: exception was thrown by a user handler's exceptionCaught() method while handling the following exception:
8:19:30 PM CONSOLE: while writev(...): Broken pipe

I've noticed that it was happening to certain members on our server. We found they were all using Java 7. Persons using Java 8, this glitch did not happen to.

After those people upgraded their Java, this glitch no longer occurred.

I'm using the latest java 1.8.0_66 64 bit and its still happening to me, I even doubled my physical ram from 12gb to 24 , still happening, in game java settings ram to 4gb

I use Java 8 and still got the glitch, but then again the machine I was playing on was hosting the server at the same time.

I am using Java 8 and am getting this glitch 😃

After further experience with this, it seems like a cross of Java and latency issues, to be honest. It seemed like anyone using Java 7 it happened to regardless of their latency. If they have Java 1.8_66, they usually can get out, but it also seems that if someone has less than 3 bars they go into the looping even with the updated Java version.

This could be because of the following observation: I've also noticed a tick of damage, and that if you don't move out of the portal you will cycle back through. It's almost as if you are being teleported into a block, then it corrects, and since you are being teleported into the portal frame, the game thinks you re-entered it.

I know the cycle can be broken by an OP TPing the player out of the frame when they appear.

Also, one last observation: If you log off in the looping cycle, people appear to be teleported to the corresponding coordinates in the opposite dimension. For example, if they're at 100 70 100 in the nether, they will appear when they relog at 100 70 100 in the overworld instead of at the 800 70 800 they should have appeared at. This can also happen the other way around. Which is a bit problematic if you happen to be over a lava lake like one of my unfortunate server mates. (EDIT: I was able to confirm this last observation. One of my server mates the other day died from fall damage after logging off after originating in the the overworld and getting stuck in a loop cycle. I teleported to the corresponding coordinates in creative mode in the nether and was able to find his stuff since those chunks were unloaded.)

What James states above seems to be a reasonable explanation. When moving from the overworld to the nether, in the case of trouble I can hear lava sounds as well as fire, which can no longer be heard when actually at the correct portal location. So there seems to be a combination of faulty spawn location + portal correction leading to a cycle back through the portal. Other players have reported appearing from their portals on fire, or having several hearts of damage inflicted upon them as if they had been suffocating in a block.

While all users do report taking damage on occasion, only those with less capable connections or with high ping to the server report cycling between portals. The cycling seems to further harm the ping to the server and their capacity do load chunks, often dropping them to a single bar. Furthermore, when using the portal in amplified terrain, I have on occasion spawned above the nether ceiling at the approximate location my overworld portal is at after logging off when stuck in a problematic cycle.

Still a thing in 50a .. would be nice to see this reoslved

I'm only experiencing this one-way on the newest java 8 version... For me this happens only from nether-overworld-nether e.G. If I stay still I end up in the nether

Video of the glitch happening

Is that in singleplayer?

Can confirm for 15w50a, SMP

Can confirm for 15w51b in SMP. I hope it gets fixed soon! I need the nether... 😛

"Workaround:
Log out and back in while you are in the correct dimension. Note that when doing this you can occasionally find yourself at incorrect coordinates."

The workaround mentioned is only if you log out in the dimension you originally started in.

If you start at 8 70 8 in the overworld, you will find yourself at 8 70 8 in the nether (instead of 1 70 1) if you mess up and log off at the wrong moment. Not a big difference there.

However, if your try this at 800 70 800, you'll find yourself at 800 70 800 in the nether though you should be at 100 70 100 in the nether instead. This difference is major at far distances.

**This is not a true workaround if executed incorrectly.** It is because the translation is occurring after one spawns in the opposite dimension. If you're close to the origin or spawn point, the translation will be much less noticeable.

Please note: Logging off in a cyclic state may result in your coordinates being exactly the same in the opposite dimension. (Ignoring Y for this...) That means if you were supposed to be 800 x 800 in the overworld, you may end up at 800 by 800 in the nether. If you then go through a portal in that spot in the nether, you will go to about 100 x 100 in the overworld. This is, again a glitch that needs to be fixed as soon as possible. I can only imagine people getting stranded 1100 blocks away in this particular scenario. And it gets worse the further out you are!

This has been happening to me for the last few snapshots, currently 15w51b. This only occurs in SMP a copy of the world opened in SSP works as expected.

I have sometimes been able to make it through a portal by tossing an item in first, but usually get stuck in a loop.

While stuck in the loop between portals I took 1/2 heart suffocation damage. Clearing out the blocks at the overworld portal location in the nether fixed that. Did the same for the nether portals location in the overworld.

I have placed command blocks with pressure plates on them at the overworld coordinates of the nether portal and if I try to run out of the overworld nether portal while stuck in the loop I get teleported by them. So the problem seems to be with the coordinate translation between dimensions not happening fast enough.

My current work around is to logout and log back in, this results in one of the following.
1) I'm still trapped in the portals
2) I'm in a portal but can leave it in time.
3) I'm at the overworld portals coordinates in the nether
4) I'm at the nether portals coordinates in the overworld

Been happening in all 1.9 snapshots. very hard to escape

One more thing that may help Mojang with this glitch that I found:

== This requires two people.
1. Create a portal at 800 x 70 x 800 in the overworld.
2. Have an observer go to about 800 x 70 x 800 in the nether and have them watch that point.
3. Have a tester go through the portal in the overworld.
4. The observer will see the tester appear momentarily at the exact coordinates they were in in the overworld when they teleported.

This is, what I believe is causing the random suffocation and/or fire damage to people going through the portals. If the exact coordinate location in the nether to the overworld is solid blocks, they take suffocation damage. If that location is lava, the person using the portal catches on fire.

There is another side affect of this occurring. It is basically generating new chunks the first time a portal is used that more than likely never will be seen (especially at extreme distances such as 1000+ off of the origin), which taxes servers as well as potentially clients. This may also be contributing to people with slower connections or computers not being able to load fast enough to get out of the portals before looping occurs: The client is trying to load two separate areas? In the example above, it would load the chunks at x=800 by z=800, then immediately being forced to load 100 x 100. Finally, the teleporting after translation seems to have broken the function that once you teleport to another portal, you don't go back through it. Because you are teleporting to another place then the game places you inside the portal itself, it's like you moved out of the portal then back in?

Hopefully this insight helps. I've used it to fire-proof and damage proof portals on our 1.9 15w51b world. Removing the lava and blocks from the corresponding locations has made nether portal travel much safer.

Is there any work-around for this? the logging in and out is not reliable.

Is there not a teleport command that can be used to teleport to the nether in vanilla. Or perhaps the use of command blocks? All the command block tutorials I see just spawn a portal which will only cause the same issue.

I would like to work through getting to the end, but this bug means there's no way to accomplish this without cheats. I understand it's a snapshot and not meant for final gameplay, just wondered if there's a way to bypass the portals until a stable release?

(btw this still happens in 16w02a)

To further @unknown's comment, logging out and back in while stuck in the portal loop has a chance of spawning you in either the overworld or nether at the coordinates of the portal in the other world.

This includes possibly ending up on top of the ceiling of the nether.

I have a similar issue on the snapshot 16w02a
On a laggy server, when i GO to the nether, i become stuck teleporting between the dimensions. I dont get suffocated, but i cant leave until do the /kill command and return to bed.
Tested on aternos.org

@@unknown: this is likely the same issue. You only receive suffocation damage if there are solid blocks at the coordinates of one of the portals but in the other dimension.

I actually put my server on a hiatus due to this issue, we were all at the point where we had just started going to the nether rather regularly, and then the next snapshot started killing us.

A MINIMAL WORKAROUND I'VE FOUND:
Disclaimer: while not very efficient, it at least fixes suffocation, though I haven't had any issues with porting back and forth either (My server's personal experience!). the procedure must also be repeated for all portals, that you want functional. You can temporarily disable portals you don't want used in the meantime. This worked for my server, I suppose I should say success may vary, though. Worth a try.

1: Copy the map over to single player.
2: Go to the coordinates of the portal in both dimensions and write them down.
3: In creative, clear a large (like 10x10x10 area, just to be safe) at the coordinates in the OPPOSITE dimension of each coordinate. (if overworld portal is 30, 5, 62; then clear those coordinates in the nether, and vice versa.)
4: Copy edited map back over to server.

What bug this gets past is when using a portal, the game initially puts you at the coordinates of the dimension you just left, and this commonly means that when teleporting to the nether, the game attempts to teleport you into inside a wall, which sends other red flags up that attempt to cancel out the port as if you never ported to begin with (this happens before the server can realize that where you should have been ported to was actually clear, but its undone before it can actually fix that), though since you were ported to inside a wall, you also take a tiny bit of suffocation damage each time. When it teleports you back, you are considered at the coordinates of the portal you just left (the actual portals coords, not where the game originally mentally put you) So then you are once again stuck in a wall, even if everything is properly rendered as if you were at the appropriate coordinates. Clearing the areas makes it so that you are no longer accidentally placed in a wall, and no longer sends the red flags of error to cancel out the portal, which now gives the game enough time to actually know you are where you are supposed to be when taking a nether portal.

This is still a problem in the new 16W03a snapshot. Just tried it hoping that its fixed and still can't get to the nether in creative mode. I switched to survival mode and was able to make it through but did take 1/2 heart damage.

Another workaround is to record the coordinates of the bottom obsidian blocks of the portal and then place command blocks at those coordinates in the opposite dimension. Put /tp @p[r=3] <some location near the portal> in the command block and then pressure plates on top.

Still an issue in the 16w05A snapshot. I was hoping it was one if the bugs that they fixed but didn't list.

Confirmed in 16w05b SMP

Confirmed this problem still is in the version finally carrying 16w05b

I have the same problem

Bug still extant, improperly marked as fixed. (As of 16w05b)

The bug was only marked resolved today, i expect the patch will be released next snapshot.

Fix Version/s: Minecraft 15w43a, Future Version - 1.9+

That means: Was at first unsuccessfully fixed for 15w43a and fixed again for the next upcoming snapshot.

Reopen per MC-89928?

this issue is about the constant transport and no way out of the transporting, that issue is about sometimes not placing at the correct coordinates, aka, diffrent issue

That ticket has nothing to do with this bug.

The bug occurs in the latest snapshot

Gilmar, that is MC-89928 (response from attached screenshot)

Yes!

Actually, I'd warrant to say that MC-89928 is what was causing MC-90605... The fact that the game was teleporting you into the portal, then it teleports you to the location you were in the overworld again, and then back, was causing load time issues, and it also 'broke' the functionality that you couldn't teleport after you teleported into a portal frame (because technically you left it and came back).

This can be seen if you are standing on the otherside of the portal when someone teleports in. Say you are teleporting from 800 x 70 x 800 in the overworld to the Nether. At the nether portal at x=100 z = 100, they appear, disappear then reappear. If you are observing at 800 x 70 x 800 in the nether at the same time, you'll see the player appear and then disappear. This is also why people sometimes take suffocation or fire damage... if there is a block or lava at 800 x 70 x 800 in the nether, they'll take whatever damage from what blocks are in that location.

Look, MC-89928 (coordinate / dimension mismatch) and MC-90605 (bouncing between dimensions, possibly either caused or exacerbated by MC-89928) are at their core separate problems. The real question is: Yesterday the Fix condition for the bug I am commenting on (MC-90605) said "Future 1.9" while today it says "16w06a".

Can anybody confirm whether or not the bouncing effect is happening in 16w06a or not? If so, then MC-90605 is not fixed. If MC-90605 is fixed while MC-89928 is not, then we need somebody to describe what now happens instead of bouncing. Do you get stuck in the wall at the wrong coordinates? Does everything work perfectly? What's up?

I personally cannot easily test this because I've never been able to reproduce without multiple players on an SMP server.

Watch the videos I posted on MC-89928
Nether: take 1 tick of suffocation/fire damage if coords in other dimension are in wall/lava and lots if lag