it happend to me too, you had to close the game, go to the game folder, delete the shader folder and then go to steam and correct files https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335&l=spanish , then you had to actualice your video card drivers and then you are good to go. hope it works for you.

Doesn't Work ! Thx anyway

Up !