I keep having this problem where NPCs, often important ones I have quest objectives with, keep turning violent without provocation, and I can't make them stop without loading a save ridiculously far back. Its happened twice now, with the most recent one seeming to start after two Whiterun guards ran up to me, told me I was wanted for something, and after invoking my get-out-of-jail free thane thing, they pulled swords and started chasing me, along with Imperial soldiers I encountered on the road. I'm part of the Imperial Legion on the character in question. And then Jarl Balgruuf started attacking me when he detected me, along with everyone else in the room. I want to know if anybody has a solution, because I'd prefer it never happened again.

One thing I can think of is if you have reached a stage 4 Vampire people will attack you automatically.