Minecraft 1.16.4
Forge 35.1.37
AlexMobs: 1.5.0

I was just idling in the world for about 20 min and then the server just crashed.

Crash Log:
https://gist.github.com/Yourname942/8aec87784f70deaa06055e8db97a4d4c
Latest Log:
https://gist.github.com/Yourname942/ea38ec7ed065c7ac3d8fc3dae2a18a71