What happened:
Upon entering the water into most likely the swim animation, the game has a ticking player crash with the exception stated in the title. This occurred on a profile on the most recent forge version, 39.0.20, and the latest version of the mod. Nothing else was added into it. To recreate it, just drop into a 2 block height of water. Easy instant crash.

Logs:
crash log - https://pastebin.com/xCH22VFZ

Versions:
MC version: 1.18.1
Forge version: 39.0.20
Mod version: 1.3.0

crash-2022-01-17_03.07.54-server.txt
same problem

i think thats also my problem, but i had a mod called not enough crashes...
so i guess, if you look at my issue, youll maybe find same problem