The world generation screen reaches 100% and then lags for about 5 minutes before shutting itself down. It throws this crash report:
crash-2021-12-05_23.57.15-server.txt
latest.log:
latest.log

Other mods are installed, but the crash report only seems to mention cosmetic armor. This problem doesn't happen consistently, and this is the first and only time I've had this happen.

Gonna close this issue, I don't think it's cosmetic armor as I just managed to get it to happen again after like 10 tries without the mod installed. No clue why it was mentioned in the crash log; if you wanna check it out, go ahead, but I think this isn't related.