Minecraft 1.12.2
Forge 2780
Primitive Mobs 1.2 Alpha
Multi Mobs 1.0.1

Description:
Server just randomly crashed out of nowhere

Crash Log:
https://hastebin.com/avikopeyoq.rb

Can you check if this still happens in the latest Beta version? I have no idea why the Grove Sprite would try to get that class on a server side... are all your players up to date?

So far so good. That being said, the crash was kind of spontaneous and not really on initial startup, so we'll see if it happens at some random point.

Thanks! It's a confusing issue for sure.

That's a bug in Grove sprite trying to use a client side only class in a dedicated server environment.

Found the issue. Should be fixed in 1.2.2a.