So I'm playing through the Soul Cairn area of Dawnguard, and I noticed a small bug where I couldn't speak to Serena in the Soul Cairn without her turning on me and attacking me like crazy. I ignored that bug thinking not much of it, I never talk to her anyways. But now we've just found her mother, but I can't talk to her mother because Serena attacks me. I tried just ignoring Serena but she kills me, I've tried running away and coming back in sneak mode, that didn't work. Now I can't finish my quest.

I found some similar bugs, but they are on PC, and were fixed by replacing the AI command or something I can't do.

Thanks so much, and I hope this isn't a silly question!

- Susitea

Did you accidentally hit her with something, or use a spell that caused her harm? I would just load a save from before she started attacking you and try it again. If you have no saves back that far, try calming her down with something. Seems unlikely she is going to be attacking you because of a bounty, but check just to be sure, if you have one make a run for it and go pay it off.