Basic rundown: If I install Mo' Creatures without the custom spawner, the game works fine but no Mo' Creatures mobs spawn. If I install the spawner, I get stuck on the loading world screen. No crash log as it doesn't crash, just gets stuck and I have to end the process with task manager. I'm fairly certain it's having trouble with AoA and maybe DivineRPG.
I am running 1.12.2.
Mod list (besides Mo' Creatures and Custom Spawner):