Game breaking bug - fallen through floor

[Addsy]

Hi guys. Don't know if anyone else has experienced this but when I went to access Brandon Wan's computer in his room on the Theta Entrance part of the game, my character fell through the floor and just kept going. All I get when I load my game up now is a black screen with a dot in the middle which I'm guessing represents the game assets being really far away because I've fallen so far.

My only other save game before this is over an hour and really don't want to go back and do all the previous section again.

Hoping someone has some suggestions of a fix?