1.20.1 Can´t Join Modded Server "Book" is Null

[ZeroTronix]

Hey i put a modpack together and the server runs but nobody can join the server because you get 

Internal Exception: io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Cannot invoke "net.minecraft.resources.ResourceLocation.toString()" because "book" is null 

i searched for the error but couldnd find anything

Client log: https://mclo.gs/0ha2gTa
Server Log: https://mclo.gs/wdpqnH3

[warjort]

That's a network error caused by one of your mods.

The error message does not appear in either of the logs you posted.

It could also be a broken custom recipe, e.g. in a datapack you have installed or some other configuration.

 

You can try adding the following system property to your jvm properties. Which should show the full error message in the logs/debug.log

Quote

-Dforge.logging.mojang.level=debug

I have no idea how to do that with the prism launcher but it should be in a similar place to where you specify the memory allocated to the game.

 

Failing that. The only way to find this kind of problem mod is to remove mods until the issue goes away. Backup your world before removing mods.

 

Your client log also contains this error:

Quote

[21:46:27] [Netty Client IO #9/INFO] [ne.mi.cl.ForgeHooksClient/CLIENTHOOKS]: Client has mods that are missing on server: [essential, smoothchunk, appleskin]

which may or may not be relevant?

 

The server log says that essential mod is broken.

Quote

/home/********/g564884/minecraft-forge/mods/Essential-forge_1-18-2.jar

[15Aug2023 21:45:05.643] [main/FATAL] [cpw.mods.modlauncher.TransformationServicesHandler/MODLAUNCHER]: Encountered serious error loading transformation service, expect problems

java.util.ServiceConfigurationError: cpw.mods.modlauncher.api.ITransformationService: Provider gg.essential.container.loader.stage0.EssentialTransformationService could not be instantiated

That mod is a custom networking layer for minecraft. It might be breaking things even when you are not actually using it?

If you are using it, then you need to ask them for support.

We cannot support that mod. It is closed source and as I said, completely changes how the networking works.

Edited August 15, 2023 by warjort

[ZeroTronix]

Thank you a lot i was throwing stuff arround and found the mod that was causing the problem

Patchouli on version 1.20.1-80-FORGE 

i removed it and Runecraft because Runecraft need Patchouli and it works.