10 Fixes for the “VAC Was Unable to Verify Game Session” Error

Have you just sat down for a match or two in Counter-Strike: Global Offensive, but you were hit with a Matchmaking Failed error due to something called VAC?

Don’t worry! We got 10 fixes for the “VAC was unable to verify game session” error that you can apply in no time and get back to playing with your squad.

Let’s lock and load! 

10 Ways to Fix the “VAC Was Unable to Verify Game Session” Error

Valve uses the VAC system in the Steam platform to deter cheaters from relying on an unfairly gained advantage in multiplayer games. However, this anti-cheat technology is not infallible and can cause an error that stops players from launching an online session.

Thankfully, whenever you encounter the “VAC was unable to verify your game session” error, you can quickly resolve it by applying one or more of the fixes below.

1. Verify the Game Files

The first thing you can try out is verifying your game files:

1. Open Steam and navigate to the ‘Library’ tab;
2. Find the misbehaving game and right-click on it;
3. Select ‘Properties’ and go to ‘Local Files’;
4. Tap on ‘Verify integrity of game files’;
5. Wait for the check to complete, and restart the game to see if it works.

2.  Check If You’ve Been VAC Banned

Perhaps you’ve been VAC banned, and you are unaware of it? Check it like this:

1. Log in to your Steam account and go to your profile;
2. Look for the VAN ban message in red letters beneath your status.

You can also use the VACBanned site for additional details, such as the current ban status, country of residence, first ban record, and past nicknames.

If you have been banned, there is no fix for this error, and you’ll have to create a new Steam account to play your favorite online games.

3. Restart the Game and Steam

Try re-launching the Steam client and your game:

1. Leave your current gaming session and restart your game;
2. If the issue persists, quit the game again and restart Steam;
3. Launch the game and see if you can replicate the issue.

4. Log Out and Log Back Into Steam

You can also relog into the Steam client:

1. Click on ‘Steam’ in the client’s upper left corner;
2. Tap on ‘Change Account’ and ‘Logout’;
3. Re-enter your login credentials to sign back in;
4. Launch the game to see if the error has been fixed.

Note: You can also try fixing the issue by logging in with a different Steam account.

5. Repair the Steam Client

The Steam client may also require repairing: 

1. Launch your favorite command-line utility as administrator:
2. Type in the following: "C:\Program Files (x86)\Steam\bin\steamservice.exe" /repair;
1. You will have to use a different path if you installed Steam elsewhere.
3. Wait for the process to complete (you’ll get a confirmation message);
4. Start Steam and the game anew and see if you can replicate the issue.

6. Repair the Library Folders

You can attempt to repair Steam’s library folders in a few steps:

1. Quit Steam and re-launch as an administrator;
2. Go to ‘Settings’ and tap on ‘Downloads’ in the side menu;
3. Tap on ‘Steam Library Folders’ to open the ‘Storage Manager’;
4. Click on the three dots next to the storage bar;
5. Tap on ‘Repair Folder’ and wait a few seconds;
6. Re-launch the game and try to replicate the issue.

7. Exclude CS:GO From the Windows Firewall

Maybe the game in question is not let through your Windows firewall? Do this:

1. Press the ‘Win’ button and type in ‘Windows Security’;
2. Once opened, click on ‘Firewall & network protection’ in the side menu;
3. Tap on ‘Allow an app through firewall;
4. Click on ‘Change settings’ to be able to make adjustments;
5. Locate CS:GO and tick both ‘Private’ and ‘Public’;
6. Restart Steam and relaunch the game.

8. Re-Download the Steamservice.dll File

You can also try deleting and re-downloading Steam’s dynamic link library (.dll file):

1. Quit Steam and go to C:\Program Files (x86)\Steam\bin;
2. Locate and delete the steamservice.dll file;
3. Re-launch Steam and wait for it to download the file again;
4. Launch the game to see if the error has been fixed.

9. Run Your Steam Client as the Administrator

Running your programs with administration permissions often fix most issues:

1. Quit Steam and right-click on your Steam icon;
2. Press ‘Run as administrator’ and click ‘Yes’;
3. Once Steam launches, start your game and check for the issue.

10. Reinstall Steam and the Game

If all of the above fails, you can also try reinstalling both Steam and the game:

1. First, uninstall the game from your Steam library;
1. Right-click the game’s icon and go to ‘Manage’ → ‘Uninstall’.
2. Next, uninstall Steam from the Control Panel or a third-party uninstaller;
3. Restart your PC and download the latest version of Steam;
4. Install Steam, and re-download the game in question;
5. Launch the game and check if the error persists.

What Causes the “VAC Was Unable to Verify Game Session” Error?

Apart from the apparent cause—cheating in online Steam games—the VAC error may also pop up for several commonplace reasons, including but not limited to:

• Corrupted or missing game files;
• Conflicts with third-party software;
• Issues with the Steam client itself;
• Connection issues with the Steam servers;
• Conflicts between the game and the operating system;
• Non-cheating third-party game mods;
• Incorrect configuration of the Steam client or game files.

Note: Before looking for the root of the problem and its solution, always ensure that your game is up to date and your network connection is working properly!

Bottom Line

Ultimately, if you are not actively cheating in VAC-supported titles, the system can’t stop you from enjoying your favorite online games. All you need to do after encountering the VAC error in your video game is to go through our list of quick and easy fixes outlined above and try them out in descending order. We guarantee you’ll find a solution!