
How to fix VAC was unable to verify your game session in CS2
‘VAC was unable to verify your game session’ is a pretty common error that’s been creating some Counter-Strike headaches. Here are some steps you can take to fix it!
Counter-Strike is a fairly polished game. Yes, it has had its issues since release but overall, things are generally working as they should. Unfortunately, when things do break, it’s usually the user that’s left high and dry. This specific error happens when someone tries to queue for matchmaking only to be told that the game session cant be verified.

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What is VAC?
Valve’s Anti-Cheat software is the tool Steam and Valve use to root out and punish hackers and cheaters. It monitors for forbidden programs, known exploits and hacks. When an account is found to have made a violation, they receive what is called a VAC ban. It’s not flawless and there was a wave of false VAC bans but fortunately, they were later lifted. These bans prevent the player from playing on VAC-protected servers, and also affect whether a user can trade and sell things on the community servers.
One of the reasons you could see the CS2 VAC was unable to verify your game session errors is that you’ve received a VAC ban. If so, there’s nothing you can do – VAC bans are issued automatically based on detected cheats and changes to game files. There are no appeals, nor are there ways to get unbanned, ever. If your account has a VAC ban and you can’t verify your game session, that’s that.
How to fix the VAC verification error
Assuming you have no VAC ban that prevents you from playing, there are several steps you can take to try and resolve the problem. We recommend you try these in order – most times the ‘Matchmaking Failed – VAC was unable to verify your game session’ error can be resolved with the first few.
Double-check there is no VAC ban on your profile
If there is one (no matter how old) you won’t be able to play on VAC protected servers or in VAC protected games. Make sure that you aren’t using family share with a VAC banned account as the same thing can happen.
Restart your PC
It’s a common solution, but one that works. Restart your PC completely and try again. Sometimes temp files can cause verification problems, and restarting clears them.
Verify the integrity of your game files
- Go to your Steam library
- Find the CS2 entry and right-click on it
- Click on the last option in the menu, ‘Properties’ and then ‘Local Files’ at the top
- On the left you’ll find ‘Verify integrity of game files’. Click on it and wait for the process to finish
- Restart your PC and try again.
Repair your Steam client
- Close Steam completely (even out of your system tray in the bottom right corner, by clicking the little steam icon and selecting ‘Exit’)
- Press the Windows key and R at the same time to open the Run menu
- Copy this text without the square brackets and press enter: [“C:\Program Files (x86)\Steam\bin\SteamService.exe” /repair]
- A terminal window will pop up and close again on its own.
- When that’s done, restart Steam and try again.
Reinstall Counter-Strike
If the other steps didn’t help you, you’ll have to completely uninstall the game.
- Go to the CS2 entry in your library, right click it and click on the ‘Uninstall’ option just above ‘Properties’.
- Confirm you want to delete the game and then reinstall it when that’s done
- Don’t forget to restart your PC when it’s done and then try again – you shouldn’t see the ‘Matchmaking Failed – VAC was unable to verify your game session’ error again!
Miscellaneous Fixes
There are a few other things that can also prompt a ‘Matchmaking Failed – VAC was unable to verify your game session’ error. These will depend on the unique conditions of your computer, and there isn’t any single fix for all of it. If the above steps didn’t resolve your problem, look into things like updating your drivers or your Windows installation, run Steam as an administrator, and whether or not your antivirus protection blocks elements in Steam or CS.
If you’re part of Steam Beta mode, then that too can cause issues – you will want to opt out and try again!