Not sure why, but in the newest version (1.20.1-0.9.15), this crash happens upon trying to join a world, even one that's newly created.
crash-2024-09-19_02.25.23-server.txt
This does not occur in 0.9.14.

Also side note, but for some reason the Sculk Tomb doesn't always generate? It wasn't there at all - maybe because the place it usually generates was overlapped by another structure? Odd...

This does not occur in 0.9.18.

Where did you get that version?

Apologies, I meant 0.9.14 - the previous version.

I will investigate this