java.lang.NullPointerException when trying to join servers

Seems to be related to a invalid session ID that only happens on the new launcher, hmm

Hi, I've had the same problem after my client updated. I can't access the server I play on and I have the same error message.

I play on a Mac.

You still have the issue in 17W06A?

What is 17W06A?

17w06a is the newest Minecraft development version AKA Snapshot.

To get it, you need to enable that in the Launcher.

How do you enable it in the launcher? Do I need to enable it?

See this for information about the snapshot and how to get it.

I don't think I want the snapshot. I just want my client to be fixed or rolled back, so I can get onto my server.

I'm having exactly the same issue & I've just tried to go on the Snapshot version and whilst the problem has disappeared, when trying to join digital forge serve I get "outdated server" and then Hypixel, I get told I should be playing on one of the older versions. Please solve this soon, I only bought minecraft the other day & it's kinda disappointing... :/

Hi guys,

Guess what! I fixed my launcher myself. I deleted my java. It works now. So, perhaps this will work for you since java is the thing that is conflicting. Good luck. Have a nice day. Thanks to the mods for trying to fix this problem. Cheers.

I configured my launcher to enable snapshots and launched with the new snapshot you referenced, 17w06a. I was not allowed to connect to Hypixel (it says it only supports 1.8-1.11), and when I tried to attach to another server my daughter was unable to attach to, I receive a different version of the same error message, "Outdated server!"

@unknown, you should use 17w06a server. You can get it from minecraft.net snapshot page

I don't want to use a 17w06a server. I want to be able to use ANY server, the way I could before. The servers I used aren't upgraded beyond 1.11.2.

Got this Error while trying to connect through the home LAN.
It Worked great BEFORE the launcher update.
Both Machines see the correct address and port ...yet I get the java.lang.NullPointerException
As Adelheid Brown suggested I renamed the Java directory for both Machines so it would install a new version ...as it did ....NO LUCK ...still gives the error.
PLEASE ELEVATE!!

If no easy fix can be found, could you at least come up with a way to let us revert back to the previous launcher? Whatever you changed with that seems to be the cause.

FWIW, I've updated all my drivers, my Java, my Windows 10. I'm on an HP Pavilion dv7 Notebook. Everything's up-to-date, Windows is getting sick of me querying their server for updates (okay, not really, but almost!). So far this issue isn't even assigned to anyone, f'real? Wow. That sucks. I've seen this issue all over the net, but I suppose most people just don't know how to report bugs. 😞

This is making me so pissed right now. I've tried all the things others have tried, and none of it works. it wasn't happening before the new launcher. can u PLEASE FIND A FIX???

I figured out that all you have to do is nuke your minecraft folder(after backing up your saves of course) but don't delete the minecraft launcher because that how you get al the minecraft stuff back

Collin Woolson - Yup, worked for me. Thanks!

Just renamed my .minecraft folders under AppData/Roaming to something else. Had to log in to the launcher again, then it re-downloaded everything, and now I can use servers again. Don't know if it works for everyone, but it worked for two of us, at least! Thanks, Collin! 🙂

That solution worked, thank you very much Collin!

MAC USER FIX

Make another computer account in 1.System Preference then click Users & Groups, and so on.
Then you sign out of original account and sign into new account. You should already have Minecraft downloaded, so just sign into your Minecraft account, make sure you can play, then go back to original account and you should be able to play!!

JacuzziLaFleur, thank you so much for the Mac fix. My daughter is up and running again!

Try to log out in the launcher and then login again.

GoodKingFilms thanks it worked

I´ve got the same problem.
Guess what, login out and then in again works...
Thanks GoodKingFilms

Persists in 17w15a, Just updated my server and got this on connect.

Much more severe this time ... It does this every time!

Tried logging out/in with official launcher (usually use MultiMC) did not resolve.

Further info:

Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at h.a(SourceFile:47)
at bgu.aw(SourceFile:951)
at bgu.a(SourceFile:399)
at net.minecraft.client.main.Main.main(SourceFile:123)
Caused by: java.lang.NullPointerException
at bqs.a(SourceFile:461)
at jh.a(SourceFile:42)
at jh.a(SourceFile:11)
at hb$1.run(SourceFile:13)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at h.a(SourceFile:46)
... 3 more

I'm experiencing the same issues as Nigel Todman. Some further info:

Happens when I join a server (notably a private survival), or after a few minutes of play.
At one point the debug window was spammed with over 5000 of those 'error executing task' 'NullPointerException' messages, with varying class names (jh, jc, etc.). Only happened once.

It isn't consistent. Sometimes it kicks me instantly, sometimes I can move for a few seconds, sometimes I can play for extensive periods of time. It also seems to depend on location. It occurs mostly in my base. I've never seen it happen in the nether. Don't know if this is actually the case, just some notable observations.

Occurs in bouts. Sometimes there's an episode of a couple dozen times, sometimes it doesn't happen.

It appears to not be a server side issue as there are no messages on the server, only on the client, and only that one time.

Things I've tried:
Renaming .minecraft for a reinstall of the launcher info.
Logging out, then back in, in the launcher.
Logging out, then back in, on my computer account. Seemed to temporarily pacify, although it still happened.

Specs: MC 17w15a, Java 1.8.0_74 64bit, macOS 10.12.

It doesnt always devolve into a persistent loop of them. Was able to play briefly on an updated 17w15a server.

But eventually it did.

Was able to play 23 minutes on my recent Livestream. Then a string of persistent nullPointerException issues.

https://www.twitch.tv/videos/135256600

Switched to single player for remainder of stream.

Also as I can continuously connect. The server instance still remains. It is just the client that is crashing.

I notice that the NullPointerException happens mainly when/if there is a parrot on the screen.

My spawn has some parrots in a glass box. If i stand there. I get NullPointerException, If I can get on the server and tp away from spawn where there is no parrots before they load. No NullPointerException error.

Getting the same problem with a parrot.
Private server was fine until the parrot we tamed appeared. It didn't follow us or teleport to the main base when originally found in 17w14, so we went back looking for it today after updating. It only teleports within a very small number of chunks...maybe the render distance?
now that it appeared no one can connect to the server without the error every one else is reporting... (we all went looking for it as only one spawned in about 2.5 hours of looking).

I can't attach the client log it seems, but it has lots of this:
[20:05:16] [Client thread/WARN]: Received passengers for unknown entity
and loading 157 achievements all though it

We are also experiencing persistent NullPointerExceptions ... deleting our profiles does not help.

This issue has been coming up recently for a few of our players. It will happen at random times, usually the player can join the server and play normally for a few minutes. After a short period of time, the client either crashes abruptly, or when opening a GUI (crafting, etc).

Things we have tried:

• Allocating more RAM to client

• Reinstalling .minecraft

• Logging in/out of the Minecraft launcher

Using Minecraft 1.12-pre1

https://pastebin.com/QeWSMzwm

For me it happens only on premium servers, cracked are working well...

@unknown That's because you can join cracked servers with an invalid session ID.

I think this error came with Launcher version 2.0.805/6.

Is this still an issue in Minecraft 1.13.1?

For me i cannot reproduce this bug i can play in multiplayer