I have a white material with a diagonal white line actos my screan

like the title is i dont know haw to remuve the material its anoying and i cant see almost enything

Hi !

This glitch appear when you have "DirectX 8.1" placed in your Garry's Mod launch option.

If you changed something with "DirectX" in your launch option, remove it. But you can also remove the "Post-Process" in the option section. If you don't know where is this setting press F1 in game.

If what I said didn't worked, please take a screenshot with your problem. Otherwise good game !

Try this work 100%.
http://steamcommunity.com/sharedfiles/filedetails/?id=154207273