In short, the Aversion Obelisk (which prevents mob spawns) won't work with incontrol installed. Whether it's a altered spawn, or unaltered. Seems like incontrol is not firing the MobSpawnEvent ?

Minecracft version is 1.12.2, incontrol version 1.12-3.9.16, forge 2847

Can you describe what exactly you're doing? What are your rule files?

This issue only appears with non-clean config files
potential spawn: https://paste.ubuntu.com/p/PV56YZ4kPr/
spawn: https://paste.ubuntu.com/p/YQKtGMP3tN/

The problem is that In Control spawning will override EnderIO (which is normal). So whenever you use 'allow' or 'default' it will change whatever EnderIO set. I have an idea for a feature to prevent this but this will not be for 1.12 I'm afraid as I no longer work in 1.12

Actually I'm wrong. It's already possible. You just must make sure you don't have any rules that specify 'allow'. Only deny mobs. Don't allow them and things will be ok

https://paste.ubuntu.com/p/249NnMgMqm/ Just for anyone who may ran into this. A script like this works, just remove the "result": default/allow