Today when i was playing Stress test #35, my screen froze but i could hear myself if I was walking. But when I changed the resolution to any other than 1080, the game was working normally and when I switched it back to "1920x1080x32" my screen was showing the same frame when it froze and when I exited the server, instead of it showing my charater in the main menu like always, it was showing the frozen frame. When I restart the game the problem was fixed. It happened once when I was killing a zombie with a combat knife, and once when I was shooting someone with the AKM in the tents of NWAF.