TF2, L4D1&2 start up then crashes with no error.

[Shadow Gun24]

Yesterday, I got on tf2, it finishes with Source and Valve thing then just randomly turns off and there is no error. I've tried it a billion times and nothing happens. Same thing over and over again. Then I tried to get on left 4 dead, same thing happened, then left 4 dead 2. The same thing happens again.

If someone knows how to fix this problem. Please respond because I have no idea what to do about this problem.

Thanks

[Kwigg]

That happened to me with gmod
You delete everything
gcfs and the main files
then reinstall

[Impulse 101]

Verify your game cache.