I don't know if anyone has have this happened to them. But when I talk to the Martian man hunter at the entrace of the mission(when you get disguised0, he does not always disguise him self but opens the gate door and you can't talk to any of the 3 atlanteans ( misspelled probably). And the only way I can fix this most of the times is by logging out. If there was a thread about this I apologize.
