I was about to turn a mission in when I experienced this bug.
http://gyazo.com/e8d8d702146b197fc7d8de2dca5c26d3
http://gyazo.com/dda7c543aeace44adfea7950e700e07c
http://gyazo.com/f41b9d1c3e485a28a956337e3b77cf92
I fell through the floor. and thought that I would let you guys know, since it might happen to other people