the game keeps the screen locked plus the audio and the game keeps rolling, in the zombies

[valdecir]

today I went to play zombies with a friend of mine via lan with radmin since hamachi doesn’t work for me, I was the host and everything was running smoothly until the game crashed the screen and the audio continued and my friend fell off the session and he closed the game and when he opened the game it appeared that tr6.dll had been corrupted. and right after that I went to play alone more with the party open and gave the same problem of the locked screen. well this was my problem, if you can help me i will be very grateful.
and if you have a little confused to understand is that i am brazilian and i am using ogoogle translator since my english is horrible