Reproduction Steps

1. install Chlorine-1.16.5-0.0.1.3.jar
2. install iChunUtil-1.16.3-10.0.0.jar
3. The game crashes

Crash Report File

https://gist.github.com/Npcfanatic21/904cacea0276717374c93361f79e5fb3

Additional Information

Minecraft 1.16.5
Forge 1.16.5 36.0.22

I also have this bug on Valhelsia 3 modpack.