https://paste.dimdev.org/yejumuxehu.mccrash

That's a rather strange one, looking into it!

That is a really strange one. It looks as though an entity is actually being created during the init process, and when it's attempting to gather capabilities, my code (which hasn't been fully initialized yet) is called. Can you try the jar from this hotfix zip and tell me if that fixes it for you? dwmh-2.1.0-hotfix.zip

Actually, that should fix it regardless, I'll push out a hotfix.

The 2.1.1 hotfix is now available on CurseForge.