Easy Fixes For ‘VAC Was Unable To Verify The Game Session’ Message In CSGO

Counter-Strike GO is probably one of the most popular first-person shooter games that nearly every gamer has at least once played on a computer. On Steam, Counter-Strike Global Offensive (CSGO) is now free to play, which invites many more players to the game lobby now. Check out this post if you see black bars in CSGO.

Some users have reported that during matchmaking, they get an error message that prevents them from joining the game. The error message says, ‘VAC was unable to verify the game session’. Here, I shall discuss some simple ways in which you can overcome this block and solve this error message.

What Is VAC And Why Was VAC Was Unable To Verify My Session?

VAC is an abbreviation for the Valve Anti-Cheat system. VAC is the service that prevents cheaters and hackers from joining the lobby and use unfair methods to gain an advantage over other players. Its main job is detecting the abnormalities in the game files, which can be manipulated to provide players with an unfair advantage over others.

You can receive the ‘VAC was unable to verify the game session’ error message due to many different reasons. A possible cause as reported by many users is that Steam needs to be run as an administrator to verify your files.

Another possible reason for the ‘csgo unable to verify VAC’ error is corrupt or missing game files. Windows or other application updates can sometimes modify the game files unknowingly, causing your ‘VAC cannot verify game session’ error.

How To Solve ‘VAC Was Unable To Verify The Game Session’ Error?

As mentioned before, there can be many different reasons why VC was unable to verify the game session. Here are some simple solutions that you can try to solve this error. You can try the solutions in the order provided, as these are arranged in the way of increasing difficulty.

Solution 1: Close Any Running Scripts

There is a possibility that the Steam client recognizes all external scripts as hacks. Hence, if you are running any external scripts for any added functionality, you can try closing the scripts and then matchmaking in your game.

After closing the scripts, if you see the game run normally, you can infer that the script is conflicting with your game. However, if you still see the ‘VAC was unable to verify’ error message, you can follow the solutions provided next and start the script again.

Solution 2: Reboot Your Device

While this may sound simple and silly at first, a simple restart can fix many different problems with your Windows device. When you restart your device, the data gets arranged in the boot section after unmounting the file system. This small step can reset your Windows device, solving many errors caused by incorrect sorting of data or other causes.

Simply save your data and close all the open files on your device. Next, restart your computer using the power menu from the start menu. Once your device restarts, check if you are able to join a matchmaking lobby in CSGO. Your ‘VAC was unable to verify the game session’ error should be solved.

Solution 3: Log Out Of Steam

The CSGO updates are distributed via the Steam store. Therefore, when there is an error in the Steam server engines, there is a chance that your game might be affected due to this as well. Hence, you need to reset the Steam client as well to solve this error.

All you need to do is simply log out of the Steam app. When you log into the app again, the Steam engine checks the installation files for the Steam client. If there was a problem with the Steam client, which was causing the VAC verification error, it should now be solved.

However, if this fails, you need to restart Steam in Offline mode. To do so, follow these steps:

1. Open the Steam client on your computer.
2. Click on Steam from the top left corner of the ribbon bar.
3. Here, click on Go Offline…

4. In the confirmation dialog box, click on the RESTART IN OFFLINE MODE button.

5. Now, close your Steam application.
6. Start your Steam client again on your computer.
7. From the same Steam menu, click on Go Online…
8. In the confirmation dialog box, click on the RESTART AND GO ONLINE button.

Now attempt to launch the game and join a lobby. You should be able to go into matchmaking easily.

Solution 4: Add Game Directory To Antivirus Exceptions

Many third-party antivirus software is known to lock down important files on your system as well. This is a bug on the part of the software and is actually a very common error as seen in other games as well. To resolve this, you need to add your game directory to the antivirus exceptions list.

If your antivirus identifies your game files as malicious and locks them down, you can add your game directory to the exceptions list of your Antivirus. In Avast, you can follow the steps provided in our article where Avast blocks League of Legends by mistaking the game files as malicious.

Solution 5: Verify Integrity Of The Game Files

When you use online game stores like Steam to buy and play games, these stores usually have a game file checker, which will scan your game’s core files for any missing or corrupt data. This feature is called the ‘Verify integrity of game files’, and can be a very useful feature in maintaining your game files.

This feature tallies the index data of your game files with the that of the latest version present on the Steam servers. When the check is complete, Steam will then replace the missing files, remove the unwanted files and update the outdated ones to keep your game feeling fresh.

Follow these steps to verify the integrity of the game files:

1. Open the Steam client software.
2. Click the Library link located next to Store.
3. Right-click on the Counter-Strike: Global Offensive
4. From the drop-down menu, click on Properties.
5. Click on Local Files.
6. Under Local files, click on “Verify Integrity of Game Files“.

Now you need to wait for the Steam client to finish verifying the installation files of your game. Once done, you should be able to connect freely to the matchmaking servers, and the ‘VAC was unable to verify the game session’ error should be solved.

Solution 6: Repair Steam.exe

If none of the solutions provided above helped you in solving the csgo unable to verify VAC error, there is a possibility that there might be something wrong with the Steam client, which is causing the error with your games. Hence, you need to repair the Steam system files itself.

To repair the Steam client software, follow these steps:

1. Open the Steam window if it was minimized to the system tray.
2. Click on Steam located at the top left corner of the ribbon menu.
3. Click on Exit from the drop-down menu.
4. Open an elevated command prompt window. To do so, open a Run dialog by pressing Win + R. Type cmd and press Ctrl + Shift + Enter to launch the Command Prompt window with administrative privileges.
5. Depending on the location of the Steam client, type the following command and press Enter:
   “C:\Program Files (x86)\Steam\bin\SteamService.exe” /repair

Wait for the repair process to complete, and then launch Steam with administrator privileges. This should solve the ‘VAC was unable to verify the game session’ error on your device.

Conclusion

So there you have it. Now you know how to solve the ‘VAC was unable to verify the game session’ error message using one or a combination of the solutions provided above. Comment below if you found this useful, and to discuss further the same.