I've tried making a save at this point and reloading it. It fails.
I've tried reloading to before I leave the port and the issue reoccurs again.
I've tried moving the DLC all on to one storage device, and the issue continues.
I've deleted the DLC and reinstalled it, and it continues to give me the same problem.
Is this a known issue? What other suggestions can anyone give me? I would really like to enjoy the new DLC

EDIT: I have now tried clearing the cache and restarting, no change.
EDIT2: Deleting ALL skyrim DLC, clearing the cache and reinstalling all the DLC worked.