Hello all! I recently purchased portal 2 and have being greatly enjoying it. Well, apart from the underground bit with the gels. Anyway, I have completed up to Chapter 8 Test Chamber 5, the one where wheatley starts to play the classical music. My issue is that there are no stairs leading out of the elevator room. There is just a deep hole and no stairs. There seems to be some objects not rendered correctly as well, meaning that next to the elevator there is just blackness.