I just played The Sentinel on Advanced with a public group of 2 others. I believe we were close to the end. We just defeated one of the rock bosses, big and white and sends a homing zappy ball at you. Afterwards, a terminal comes out of the ground, and when you step on the footpad, its supposed to activate and thus allowing you to move on in the story. The footpad did not activate. We killed ourselves and came back, we all got off the platform then back on the footpad, but it would not activate. We were forced to kill ourselves and use up our lives to force end the mission without losing xp.
My match ID is