Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - Enhanced Edition Book of the Dead respawning enemies

Which mod did you get from Nexus? Are you sure it is a mod for the Enhanced Edition, and not the original release of the game?
In the Steam workshop, Book of the Dead only shows up in the EE section, so that shouldn't be causing the error.

Did you try creating a new profile, and starting a game with each mod separately? If both work on their own, that would tend to confirm a conflict between the mods.