Illusion spells stopped working?

[Ryuk0Scratch]

Unsure if it fits here but, for whatever reason my illusion spells simply ceased functioning for one reason or another, I can cast them, and the cost is still applied properly, but when they hit an NPC they only last for at max about half a second before fizzling out. I AM playing heavily modded so I can figure that would largely be the problem but I don't know which mod would be breaking the spells this badly. Any ideas or help would be appreciated.