Output in console:

[Zombie/NPC Invasion (Fixed)] lua/autorun/zinv_init.lua:98: attempt to index global 'spawnedZombies' (a nil value)
1. v - lua/autorun/zinv_init.lua:98
2. unknown - lua/includes/modules/hook.lua:84

And as bonus, when i want to enable addon, it is just writting in chat that i must be super-admin to change this....but i am host

Looking forward for idea, i have plenty of addons and i dont want to waste my time searching which one is colliding, thank you.