Hi, i am unable to join a multiplayer server my friend and i created. We started it with some mods then decided to add some others and this is when the error appeared. We are using Curseforge, the server is in 1.20.1 .
The full error message is "Internal Exception: io.netty.handler.codec.DecoderException: java.lang.ArrayIndexOutOfBoundsException: Index 17196645 out of bounds for length 13"
I am the only one with that issue, my friends can log in and out no problem. I have tried switching minecraft account but that doesn't help so i guess the bug is on my side. We use the same mod profile so i know the error doesn't come from there.
Solo works fine tho

Here is the latest.log file https://pastebin.com/X6J9Fnnf.

If you need more informations to try and investigate, please let me know.
Big thanks to anyone that will try to help

EDIT:
The issue seems to be coming from one of cobblemon's addon, as removing the all the addons from the server and my client fixed the issue. I still want to play with cobblemon so the post remains open
Edit 2:
We are trying to enable and disable addons one by one to see if one is at fault, but nothing is consistent, we know the issue comes from one/ some addons or maybe it's a combination of addons that glitch.
Also sometime we disable an addon, it works, then we reactivate it again, it stops working then we disable it again and it sill doesn't work. Madness is starting to set in.

Edited June 14, 20241 yr by noutnout27

Necroposting slightly, but I made an account just to reply to this! I found a solution that worked for me.

Cobblemon Counter seems to cause issues when it edits playerdata to store the count, I removed it and my friend with the same issue was able to join.