If you are trying to play CS: GO, and suddenly, a VAC Game session error pops up on your screen, you are not alone. Many CS: GO players have encountered this problem with matchmaking.
As you know, being unable to enter matchmaking is really frustrating because you can’t play the game. You are stuck on the home screen with nothing to do.
Lucky for you, this problem with VAC is very easy to fix. Follow the guide below to help you solve this problem.
Method 1: Restart your Steam Client
You can get this error because there are some instances where steam encounters a bug or error within its system. Restarting the client will help you in resolving this issue.
Step 1: On your steam client, click on Steam on the menu bar.
Step 2: Click on exit.
Step 3: Open Steam Client.
Step 4: Click on Steam again on the menu bar.
Step 5: Select Go Offline.
Step 6: A pop-up window will appear; Press Restart in Offline Mode.
Step 7: After restarting steam, click on Steam again on the menu bar.
Step 8: Click on Go Online.
Step 9: Then click on Restart and Go Online.
Method 2: Verify the Integrity of Steam Game Files
Step 1: Open Steam.
Step 2: Log in to your account.
Step 3: Go to Library.
Step 4: Right Click on the game that you are having problems launching.
Step 5: Click on Properties.
Step 6: Click on the Local Files tab.
Step 7: Click on Verify Integrity of the game.
Step 8: Wait for the process to finish.
Method 3: Repair Steam Client in CMD
Step 1: Press on the Windows key + S and Search for Command Prompt.
Step 2: Click on Run as Administrator.
Step 3: On Command Prompt, Type the following lines and hit Enter.
“C:\Program Files (x86)\Steam\bin\SteamService.exe” /repair
Step 4: After repairing Steam, try to run CS: GO again and see if the problem is fixed.
See Also: What to Do When Steam Won’t Open