A popular multiplayer first-person shooter game based on Counter-Strike is called Counter-Strike: Global Offensive (CS: Go), created by Valve. However, many players complained that VAC could not validate their game session while playing, trying matchmaking or joining the Steam community. You have come to the right place if you are experiencing the same issue and seeking a solution. You may experience
VACs unable to validate the gaming session problem when the temporary files on your system get old.