Originally Posted by scottttocs
unfortunately its a known glitch. the only work around is to start again or join someone elses game who is up to that point, and complete it with them.
out of curiosity, did you by any chance use the glitch to get in the armory with unlimited time, where you slip through the floor? i believe this is how it gets glitched in the first place.
Nope all i done was the mission you originally do for the main storyline of the DLC