There is a bug in fog lower, when you walk to Ember from spawn. all things on the screen dissapear (like ALT+H)
Fog is advanced place, remember your shortcuts and master gamesense.
But seriously, it happens in many parrts of fog, like whole stakato zone.
Disable "Use Improved Shader Effect" in video settings.
noooo i wanted to keep that secret fix to have whole fog for myself :<
8)