This is the crash report
crash-2020-12-05_10.34.53-server.txt

I can't even create a new world, I get the same error

Yup think I'm getting a similar error as well. Freezes at 0% when creating new world and requires task manager to be closed.

debug.log

similar problem, when i try to create a "caves" worldtype (i forgot what mod is adding that lol) loading gets stuck at 1% and crashes with error 0
crash-2021-01-10_20.03.07-server.txt
other worldtypes, except for superflat, get stuck in loading and i have to close the game through the task manager
crash-2021-01-10_20.54.34-server.txt

turns out the caves worldtype is a vanilla thing, i totally forgot

Deadly module worldgen is being rewritten, so this should vanish with that.