Passive Enemies

[blitzen]

I've been having problems recently with some enemies that aren't attacking, and often not even defending themselves when attacked. It was initially happening with some draugr from a Haunted Forests mod, which was previously working perfectly. Within the last few weeks, things changed. I just purchased Dawnguard, and now I see that some of the vampires stand around passively too. That pretty much ruins the DLC. Oddly enough, some of them still act aggressively, which makes this even more mysterious. I'm using the Unofficial Patches for both Skyrim and Dawnguard. I'm not completely sure, but I believe that the draugr issue existed before I installed even the USKP, which was something I only did very recently after updating to patch 1.8 to use newer mods. So that seems to eliminate those as causes. It seems as if the AI stops functioning. I also saw cases where the draugr would ignore the player character, but did get into combat with some animals, so it's not entirely consistent. Very mysterious. Has anyone see this before, or have ideas about identifying a cause?

[h0rsel0ver]

You're probably not going to like this, but unless somebody else knows the specific cause of this, you're going to have to disable your mods one by one until you've found the cause. I would suggest saving your game around one of these pacifists so you don't have to hunt one down as you test. Problems like this are often caused by conflicting mods

[blitzen]

I found it pretty quickly once I started actively trying to solve it. I used TES5Edit to look for mods that had conflicts with either draugr, vampires, or factions. So I only had to deal with half a dozen or so that were complicated enough to be likely to have bad effects. It was caused by an update to a mod I had been using for more than 6 months without problems.