Version Info

• Minecraft 1.21
• Fabric loader 0.15.11
• Chunk loader 1.2.8
• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

Are you using OptiFine?:
No, but with iris.

Steps to Reproduce

1. Exit server

Detals
The client will crash instantly after clicking quit button, but this problem doesn't occur when leaving single player worlds.

Crash report (~/logs/latest.log)

• The game crashed whilst mouseclicked event handler
• Error: java.lang.NullPointerException: mouseClicked event handler
• Code: -1
  latest.log
  crash-2024-07-24_01.47.44-client.txt

I don't see anything related to Chunk Loaders in the crash log and you seem to be using quite a lot of mods. Are you sure this is caused by Chunk Loaders?

Yes, I've done some tests. If I remove chunk loader from the my self-hosting server, the client will no longer crash.

==Update==
This problem may be related to SuperMartijn642's Core Lib mod, if it's installed on the server, the client will prompt saving a game, then crash. After removing it, I can now leave the server as usaul.

Okay thanks. I just left for vacation and I also just have a lot to catch up on, so it will likely be a while before I look into the issue.

No problem, hope you have a nice vacation! I also found this problem doesn't occur on Paper server, so I would switch to it as a temporal workaround.

Hmm Paper can't load Fabric mods, you did install the mods on the server as well right?

LOL so that's the reason that the client didn't crash. Yes I did install all dependencies, corelib, config, and chunk loaders. Removing chunk loader alone can't fix the problem, after removing corelib the client won't crash anymore.

Problematic

Server side

• Chunk loader 1.2.8
• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

Client side

• Chunk loader 1.2.8
• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

=======

Problematic

Server side

• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

Client side

• Chunk loader 1.2.8
• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

=======

Problematic

Server side

• SuperMartijn642's Core Lib 1.1.17

Client side

• Chunk loader 1.2.8
• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

=======

No problem

Server side

• SuperMartijn642's Config Lib 1.1.8

Client side

• Chunk loader 1.2.8
• SuperMartijn642's Core Lib 1.1.17
• SuperMartijn642's Config Lib 1.1.8

This is an issue with Elytra Trims. The author of Elytra Trims is working on a fix though, you can find the relevant issue here kikugie/elytra-trims#67
Thank you for reporting the issue of course 🙂