Xbox 360 Can't do Dawnguard quests any more

I came home to a loving wife. I went to initiate a little conversation and she blurts out a big "Thank you!" for saving her.

Huh?

I was on no quest to save her, so off I went to Dawnguard castle to get the full story. Perhaps a case of mistaken identity but, sure enough, they're convinced I'm on a quest to kill a Vampire lord and rescue my wife. With a big Kaboom the "kill" part of the quest now shows up in my list.

Never to turn down a good kill no matter how convoluted the circumstances, I went off to do in would be kidnapper. Of course, following true to form, things just got more interesting. As I follow the guiding arrow to the back of the cave I find it pointing at the ground. Alas, nobody to kill.

No kill... no quest completion, so no more quests coming my way from Dawnguard castle. Far too late to restore to an earlier time as I should have. Darn.

Had thought I'd given it enough time to reset but may not. I'll leave it alone for a good while. Will see if I can find someone else who gives quests that are at least a little bit challenging.

Damsel in Distress is usually Hearthfire, not Dawnguard. It's radiant so a vampire and the Dawnguard could be involved. AND yes, it's glitchy. I usually find my spouse back at home after a while. If you have DLCs instead of the legendary package, you could re-download the DLCS. I find that fixes a lot of things. Back home at Bethesda, they're still cleaning up glitches and patching things, so re-downloading gets you the latest fixes.

Other than that, yeah, waiting for respawn is probably the best course of action.

I've had glitches like this before. I agree with the others, just give it some time to re-spawn and try again. I would suggest staying clear of the quest area as well however.