Screen goes black in the defector

Screen goes black in the defector

I have been playing the campaign and i believe i am on the level called the defector where you run down the street have your planes target the buildings. At the end of the street there is a gate that gets kicked open then you go and push on a door. When I push on the door my game goes black and the only thing i can see is the compass and the distance to the next checkpoint. But the rest of the screen is black.