So I have no idea if this should be reported.
https://gist.github.com/P3rf3ctXZer0/92ed31b741bc52e9faecaa0fd7bea9dc

it looks like this is related to Alex's mobs.

if this happens again, then please add the crash-report file or latest.log here. You can attach them here. I'll check if it's related to Every Compat or not.