happened consistently
I was playing on the adventure pack server during a blood moon for each crash
latest log:
crash-2020-09-19_11.34.29-client.txt

crashes happen after the blood moon as well, but I do not crash opening the stat menu or opening the skill tree on different worlds.

you have older mod version. what's the server version?

unsure, but I am using the latest version of the modpack it is for so I assume we are both on 1.3.7.
The problem seems to have been resolved by me just opening the skill tree on a singleplayer world before entering the server. Since I resolved it myself and I am a few updates behind, I'll close the issue.