Running a forge 1.18.2 server on my pc and having troubles (obviously)

 

I made a custom modpack threw together a server with MCSS runs great, but when a player do certain things, they get kicked and cant log back in. I went to "carry on"' a chest and that was when it first happened so i assumed it was that mod, removed tried again. playing, eat some bread, its fine, go to eat zombie flesh, kicked again. Friend ended up getting kicked but I forgot to get his example as I was still trying to troubleshoot my food related kick.

 

The servers logs show nothing wrong, and stay up no issue, and I cant find any info on the conn. lost msg I got, nor can I see anything in the logs that would cause the disconnect. conn lsot msg is

Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(7) = length(4) exceeds writerIndex(7): PooledUnsafeDirectByteBuf(ridx: 7, widx: 7, cap: 7)

client debug.log

 

One of your mods has broken network code. There is nothing in the log or the error message you show that suggests which one.

Check you have the latest versions of your mods.

You can try adding the following system property to your java/jvm parameters to see if it gives more information in a full stacktrace for that DecoderException

-Dforge.logging.mojang.level=debug

Otherwise you will have to experiment with removing mods or search your mod's issues pages for known issues.

Is that for the command for client or server? I've been trying to get a more detailed debug, put that argument in a few different possible slots and no new info.. I'll attach the servers debug just in case

 

Server debug.log

It is both since we don't know from that error message which side the error occurs.

For the client it depends which launcher you are using. For the vanilla launcher:

Launcher -> Installations -> Edit the Forge Profile you are using -> More Options -> Add the Argument to the JVM Arguments

For curseforge there is an "Additional Arguments" in the minecraft settings.

For the server you put it in the user_jvm_args.txt

Oh hey I had done it wrong client side, I think it came up slightly different but I cant tell if its just another more detailed way for the client to say "i dont know what happened"Client Dforge debug.log

The stacktrace is 

Caused by: java.lang.IndexOutOfBoundsException: readerIndex(7) + length(4) exceeds writerIndex(7): PooledUnsafeDirectByteBuf(ridx: 7, widx: 7, cap: 7)
	at io.netty.buffer.AbstractByteBuf.checkReadableBytes0(AbstractByteBuf.java:1442) ~[netty-all-4.1.68.Final.jar%2327!/:4.1.68.Final]
	at io.netty.buffer.AbstractByteBuf.readInt(AbstractByteBuf.java:809) ~[netty-all-4.1.68.Final.jar%2327!/:4.1.68.Final]
	at net.minecraft.network.FriendlyByteBuf.readInt(FriendlyByteBuf.java:949) ~[client-1.18.2-20220404.173914-srg.jar%23218!/:?]
	at net.minecraft.network.protocol.game.ClientboundUpdateMobEffectPacket.handler$zpa000$readTail(ClientboundUpdateMobEffectPacket.java:533) ~[client-1.18.2-20220404.173914-srg.jar%23218!/:?]
	at net.minecraft.network.protocol.game.ClientboundUpdateMobEffectPacket.<init>(ClientboundUpdateMobEffectPacket.java:51) ~[client-1.18.2-20220404.173914-srg.jar%23218!/:?]
	at net.minecraft.network.ConnectionProtocol$PacketSet.m_178327_(ConnectionProtocol.java:419) ~[client-1.18.2-20220404.173914-srg.jar%23218!/:?]
	at net.minecraft.network.ConnectionProtocol.m_178321_(ConnectionProtocol.java:471) ~[client-1.18.2-20220404.173914-srg.jar%23218!/:?]
	at net.minecraft.network.PacketDecoder.decode(PacketDecoder.java:32) ~[client-1.18.2-20220404.173914-srg.jar%23218!/:?]
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:507) ~[netty-all-4.1.68.Final.jar%2327!/:4.1.68.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:446) ~[netty-all-4.1.68.Final.jar%2327!/:4.1.68.Final]

Which shows it is a problem with MobEffects.

There is a mixin in that stacktrace modifying the packet handling which appears to be from the potionidpacketfixer mod

Quote

[10Oct2022 15:05:00.112] [Server Pinger #0/DEBUG] [mixin/]: Mixing MixinClientboundUpdateMobEffectPacket from potionidpacketfixer.mixins.json into net.minecraft.network.protocol.game.ClientboundUpdateMobEffectPacket [10Oct2022 15:05:00.112] [Server Pinger #0/DEBUG] [mixin/]: potionidpacketfixer.mixins.json:MixinClientboundUpdateMobEffectPacket: Class version 61 required is higher than the class version supported by the current version of Mixin (JAVA_8 supports class version 52)

Edited October 10, 20222 yr by warjort

Looks like a known issue?

https://github.com/stepsword/potionidpacketfixer/issues/1

Yes that was the cause holy thanks much! You also inadvertently taught me how to read the debug a bit better, and how to use the dforge arg properly I'm very grateful