Description
Unable to join to 1.12.2 server (play.teslacraft.org) – disconnect with an error io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(38) + length(4) exceeds writerIndex(38): PooledUnsafeDirectByteBuf(ridx: 38, widx: 38, cap: 38)
[Demo]
Occurs even without any other mods.

Technical
Minecraft version: 1.19
multiconnect version: 1.6-beta.12
Server version: 340 (1.12.2)

Additional
latest.log

There are also many packet errors in logs.

I've also been getting errors like these, but for 1.19 -> 1.18.2

@BookWyrm114 that is not the same error. Yours looks like #359