I have a heavily altered version of ATM9. I was running my game and it was fine then it started to rain. My crash log says between ModernFix and Biome Particle Weather, so I have posted to both githubs.

Here is my crashlog
crash-2023-12-28_13.27.13-client.txt

And my Latest log
latest.log

This is not ModernFix's fault - it just optimizes the code that prints this error, but the exact same failure would occur with the unmodified code.