In my current game, I've found the secret entrance to the Iron clan, and used the glass key to open it.
I go inside, and the Magnus dialogue triggers. I go through the door in the room.....and see the attached image.
I cannot move, but I can teleport out. And more importantly, I can't get to the iron clan items or the Durin Stone.
Has anybody else had this problem? Is there a fix?
I believe I may have to reinstall, but I would like to avoid that if possible.

UPDATE: I did a clean re-install, and the issue is gone. My guess is that I had a mod installed that wasn't playing nice.