I'm using a custom modpack I made, and now when the mob spawns I crash, I do have Sponge installed. Could that be it?

https://paste.dimdev.org/terivabeqa.mccrash

I also messed with multimob configs to get the mobs to spawn in biomes o' plenty biomes.

https://pastebin.com/8T9mYLGT

Sorry I got here so late. The link no longer works. Did you ever figure this out?