We are aware of a possible issue with the mission "A Montage" in Mr. Torgue's Campaign of Carnage where players are unable to complete the mission.

Our engineers are currently looking into this.

In the meantime, you may be able to complete the mission by reloading the game or by joining a game where the host has not completed this mission.

Keep an eye on our Knowledge Base (http://support.gearboxsoftware.com/forums) for any additional details moving forward.