I have a minecraft cauldron server, and I play with my friends on it, and it works fine, however, when we tried to add the mod Advent of Ascension to the server, and to our client as well, we get the error that is in the title of this thread post and here:
io.netty.handler.codec.decoderexception java.io.ioexception bad packet id 64
And we get that in our clients when trying to join the server. I've tried resetting the playerdata (only the ones in "world/playerdata" and "Essentials/players" of the server files) and we still get the same error. It downloads the terrain, and says "logging in" then after that it doesn't log us into the game, it just displays the error.
Note: If you need any part of logs, I can provide you with that, because I have access to both server files and client files.
Any help would be greatly appreciated.
Thanks in advance.
Edit: In case you're wondering, yes I did do research, for 5 hours, and all I could find were unresolved, or things that didn't apply to me, such as:
Being IP banned
Having a different version of the mod or client on the server than on the mods (however, my client forge is the latest, while the server is running forge 220.127.116.118), that might be the problem so I'm going to test it soon and see if that fixes it)
SOLUTION: So I updated and made the server and client forge the same version, and the issue was still there. But I found out the problem, in the server console, it was an error such as this:
java.lang.IllegalArgumentException: Duplicate id value for 27!
And that means there's a duplicate DataWatcher on the server/client that's causing a conflict in Forge. So I went to Advent of Ascension config file, and pressed Ctrl + F to find "Datawatcher" then I just changed the ID numbers till they worked. These are the ones that worked for me, it might be different for you: