Biolab that have underground levels when your are at the top of staircases trying to look down does not render properly and actually I get a image of sheer white at the top until I force myself to go down.
Its the north stairs at iknam biolab, to the C point from the main bunker. (when you're running up) Also same thing erm, on the north west stairs, on the balcony of the A point building to Regents Rock. - When you are facing west and jump of the balcony towards the B poitn.