This quest was working before 1.6.
Once you get to the point where you are supposed to talk to the guy inside the mine door after knocking and while wearing the disguise, and lie to get him to let you inside, the quest updates and the door activates, but you never port inside. You are then stuck. If you activate the door again you get a dialogue that no one is there, and an option to enter the mine, which makes the door move again and STILL doesn't port you inside.
This prevents you from completing the main quest in Bleakrock, as well as getting the Skyshard inside the mine.
It seems perhaps there is a bug related to the fake "sneaking" that certain costumes put you in and the new sneak system.