Forum:Hoover Dam Black Screen Bug

I seem to have a problem. I decided to play through FNV again but this time siding with Yes Man. I go all throughout the game but once I get to Hoover Dam for the final battle, I get bugged. Here's the layout.

1)I'm Shunned with the NCR and Vilified with Legion. 2)The save in which I am bugged with is inside the Hoover Dam Offices. 3)I'm on the XBox 360

I cannot go through any door or else I get a black screen and must restart my XBox. The loading screen loads completely, makes the door sound, and my screen goes black.

Please help!