Keith David mission never stops loading

When I'm on the Keith David mission it tells me to go to his meeting.

After I survived the angry pedestrian rampage, went inside to follow Keith and killed everything in sight, I followed the marker and instructions to go into office. But once I do, it starts to load and it never stops loading. While loading it's still playing music and moving like normal, but never loads me in the office.

I've replayed the mission 6 times and cleaned my disc 2 times and I've let it load for 30 minutes, and it still did not do it. I don't know how to get it to work.

Solution 1:

Apparently there is a bug that requires you to unequip the Alien RPG before you go through the door.