Counter-Strike: Global Offensive (CS: GO) is a game enjoyed by many players around the world. But when you try to queue for matchmaking, you might encounter an error message that says, “VAC was unable to verify your game session.” Many online gamers have reported coming across this error when they try to join the Steam community or play a game.

If you are seeking solutions to this problem, you have come to the right place. We will present a handful of fixes that you can try to get rid of the “VAC was unable to verify your game session” error notification on CS: GO.

Why Does it Say VAC Was Unable to Verify Your Game Session?

VAC (Valve Anti-Cheat System) detects anomalies in installation files. It is meant to prevent gamers from making changes to game files in order to gain an unfair advantage over other players.

When VAC fails to verify your gaming session but you have not in any way tampered with your game files, it means that there is something wrong with the configuration of the files. Sometimes also, VAC could generate a false positive error and turn up the “Unable to verify the game session” message.

How to Fix VAC Authentication Error in Windows 10

Perhaps you have tried reinstalling your game but the issue still won’t go away. It is important to note that reinstallation will load the same game files again and, therefore, won’t be of any help. But rest easy: The solutions we now present to you have been found effective and will help you resolve the “VAC was unable to verify your game session” error once and for all.

How to fix VAC unable to verify my game:

  1. Reboot your computer
  2. Restart the Steam Client
  3. Log out of Steam and log in again
  4. Run Steam as an administrator
  5. Repair the Steam client
  6. Repair Steam files
  7. Verify the integrity of your game files and repair the game library
  8. Exclude the game directory from antivirus scans
  9. Stop conflicting background tasks/services
  10. End the Steam service in Task Manager
  11. Verify DLL file
  12. Delete temporary files
  13. Update your drivers
  14. Update Windows
  15. Turn off Steam Beta

Let’s now take the solutions one at a time.

Fix 1: Reboot Your Computer

Some apps and processes (such as disk indexing) that are running on your computer might be accessing your game files, and thus causing VAC to fail in verifying the files. Rebooting your computer can help resolve this. Follow the steps below:

  1. Close all apps and windows.
  2. Press the Windows button on your keyboard or click on the icon on the bottom-left corner of your screen.
  3. Click the Power icon when the Start menu appears. Then click Restart.
  4. After the restart, try running your game again and see if the error has been resolved.

If restarting doesn’t work, you can power cycle your PC. Power cycling means turning the PC off completely and then turning it on again. This will help the device recover from an unresponsive module and reinitialize its configuration parameters. Power cycling also resets your network configurations.

Follow these steps to get it done:

  1. Close all open applications and windows.
  2. Unplug the computer from its power source (laptops).
  3. Go to the Start menu (press the Windows key on your keyboard) and click on the Power icon. Then click on Shut down.
  4. Wait for the PC to power off.
  5. Remove the battery from the device (laptops), and then press and hold the Power button for up to 1 minute.

Note: The reason for removing the battery from the laptop is to properly discharge all the capacitors and ensure that the data stored in the RAM is cleared.

If you use a desktop, unplug it from the power source.

  1. Wait for a minute or two before putting the battery back into the laptop (you can plug the charger back in if you want) or before plugging your desktop to the power source.
  2. Power on the PC again and see if the VAC error will still occur in your game.

Fix 2: Restart the Steam Client

Restarting the Steam client can help resolve any corruption that’s causing the ‘VAC was unable to verify the game session’ error. Here’s what you have to do:

  1. Click on the Steam tab in the top-left corner of the screen and click on Exit from the context menu.
  2. Open your Steam client again.
  3. Click on the Steam tab in the top-left corner and click on the ‘Go offline…’ option in the context menu.
  4. Click the ‘Restart in offline mode’ button.
  5. Now, click the Steam tab again and click on the ‘Go online…’ option from the context menu.
  6. Click the ‘Restart and go online’ button.

After you’ve followed the above steps, try queuing for a match again and see if the VAC error message will still appear.

Fix 3: Log Out of Steam and Log in Again

If the fixes above didn’t help, then try logging out of your Steam account and logging in again. Your operating system or file management system might have been responsible for modifying your configuration files, causing the VAC error to appear. Logging out of your Steam account will remove the altered configuration files. The original files will then be recreated when you log in again.

Logging into your Steam account again will give the same (or even better) results as reinstalling your Steam app. Follow the procedure below:

  1. Open your Steam app.
  2. Click on your Profile name shown at the top of the window.
  3. Click on ‘Log out my account’ from the context menu that opens.
  4. After the log out is successful, enter your credentials and log in again. If you don’t remember your password, click on the “Reset password” option.

Now try your game again. The VAC error will have been resolved. If not, move on to the next fix.

Fix 4: Run Steam as an Administrator

If Steam does not have admin privileges on your computer, that could be the cause of the trouble you’re facing. The client needs full access to function effectively. Giving it admin access means it can change the system configuration files and gain the resources and memory it requires. Follow the steps below:

  1. Go to the directory where Steam is installed on your computer. This is usually C:\Program Files (x86)\Steam.
  2. Now, open the Steam folder and locate the ‘Steam.exe’ file, right-click on it, and then click on Properties from the context menu.
  3. Switch to the Compatibility tab and mark the ‘Run this program as an administrator’ checkbox.
  4. Click Apply to effect the change, and then click the OK button.
  5. Next, locate the ‘GameOverlayUI.exe’ and right-click on it. Select Properties from the context menu.
  6. Switch to the Compatibility tab and mark the ‘Run this program as an administrator’ checkbox.
  7. Click the Apply and Ok buttons.

Afterward, we now have to grant admin access to all the Steam folders, not just the two .exe files shown above:

  1. Go back to the main Steam folder (That is C:\Program Files\Steam). Right-click on it and click Properties from the context menu.
  2. Switch to the Security tab and click the ‘Advanced’ button.
  3. On the page that opens, the first four rows in the ‘Permission entries’ list are editable, while the last two rows are not.
  4. Select the first editable row and click the Edit button. On the page that opens, mark the checkbox for the options under ‘Basic permissions,’ including ‘Full Control.’
  5. Click the Apply button and click Ok to exit.
  6. Repeat Steps 4 and 5 for the remaining three editable rows.
  7. Re-launch Steam. It will now run with admin privileges. The VAC error should be resolved. Otherwise, move on to the next fix.

Fix 5: Repair the Steam Client

Your Steam client could be corrupt or contain bad files. Here’s what you have to do:

  1. Right-click on the Start icon in the lower-left corner of your screen.
  2. In the Power User menu that opens, click on Command Prompt (Admin).
  3. Click the ‘Yes’ button when presented with the UAC prompt.
  4. Copy and paste the line below and hit Enter:

“C:\Program Files (x86)\Steam\bin\SteamService.exe” /repair

  1. Wait for the process to complete. It will take a little time.
  2. Close the Command Prompt window and restart your computer. Now, check if the ‘VAC was unable to verify the game session’ error has been resolved.

Fix 6: Repair Steam Files

Performing a file repair will help fix important Steam library files that are corrupt. These may be causing CS: Go to bring up the VAC error. Follow the steps below:

  1. Go to the location: “C:\Program Files (x86)\Steam\SteamApps\common\Counter-Strike Global Offensive\csgo\maps\workshop” and delete every item inside the folder. To do this, simply press Ctrl + A,and then press Shift + Delete.
  2. Next, go to “C:\Program Files (x86)\Steam\SteamApps\common\Counter-Strike Global Offensive\csgo\maps\graphs\workshop” and, again, delete everything in the folder by pressing Ctrl + A to select the items and Shift + Delete to delete them.
  3. Launch Steam. It will download fresh copies of the files you deleted.
  4. Check if the VAC error has been resolved.

If the problem persists, then:

  1. Press the Win key + X to open the Power User menu.
  2. Click on Command Prompt (Admin) from the list.
  3. Click the ‘Yes’ button to continue.
  4. In the Command Prompt (admin) window that opens, enter the following commands (don’t include the bullets) and press Enter after typing each to execute them:
  • start steam://flushconfig
  • ipconfig /release
  • ipconfig /renew
  1. If, however, the issue remains, you may want to consider disabling some security features that allow VAC to function. Enter the following line into the Command Prompt (admin) window and hit Enter:

bcdedit.exe /set {current} nx OptIn

Fix 7: Verify the Integrity of Your Game Files and Repair the Game Library

The error can appear on CS: Go due to integrity issues with your game files. There is a feature in your Steam client that can help resolve this:

  1. Open your Steam client and click on the Library tab.
  2. Right-click on Counter-Strike: Global Offensive and select Properties.
  3. Switch to the Local Files tab and click on ‘Verify integrity of game files.’
  4. Wait for the process to complete, and then click the Close button.
  5. Launch CS: GO and see if the error has been resolved.

Next, you will have to repair the Library folders. It contains the games you installed. Here’s what you have to do:

  1. Open your Steam client and click on the Steam tab.
  2. Click on Settings from the context menu that opens.
  3. Now, click on Downloads from the left pane.
  4. Click the ‘Steam Library Folders’ button in the right pane.
  5. In the new window that opens, right-click on the install location that contains your Steam content. A drop-down menu will appear. Click on ‘Repair Library Folder.’
  6. Confirm the action and click ‘Yes’ when UAC prompts to allow access to Command Prompt. The repair process will commence. Wait for it to complete.
  7. Afterward, restart the Steam client and try running your game again. See if the problem has been resolved.

Fix 8: Exclude the Game Directory from Antivirus Scans

If the antivirus program on your computer is automatically scanning your game files in the background, it prevents VAC from verifying the files, thereby causing the error you are dealing with to show up. You can stop this from happening by whitelisting the Steam directory and the particular game you are having issues with so that they won’t be automatically scanned. The method for doing this depends on the antivirus program you are using.

Fix 9: Stop Conflicting Background Tasks/Services

If you are running virtualization software and VPN/Proxy, they could be the cause of the ‘Unable to verify the game session’ error you are facing. They could be making VAC to flag you. Here’s how to stop them from running in the background:

  1. Open the Run accessory (press the Win key + R).
  2. Type ‘Services.msc’ in the box and hit Enter or press the Ok button to open the Service Management window.
  3. Locate any of the following services:
  • VMnetDHCP
  • VMUSBArbService
  • VMware NAT Service
  • VMwareHostd
  • VMAuthdService
  • hshld

Right-click on them and click Disable from the context menu.

  1. Afterward, close the Service Management window, right-click on the Start button in the bottom-left corner of your screen, and then click on Task Manager from the list.
  2. Go to the Processes tab and locate the following processes:
  • hydra.exe
  • hsswd.exe
  • hsscp.exe
  • vmware.exe

Click on each of them and click the End Task button.

You can now check to see if the issue has been resolved. If it remains, don’t worry. Move on to the next solution below.

Fix 10: End Steam’s Service in Task Manager

It could be that there’s a problem with the Steam service running in the background. Ending it can help fix the issue. Follow these steps:

  1. Press the Windows key + X to open the Power User menu.
  2. Click on Task Manager from the list.
  3. Go to the Processes tab and click the Steam service to select it. Then click the End Task button.
  4. See if the issue has been resolved.

Fix 11: Verify DLL File

You will find a Steam service DLL file in the Program Files folder located in Local Disk C on your computer. The second DLL file is located in the Steam installation directory. If these two files differ, then VAC will not be able to verify your game session. What you have to do to fix the issue is to copy one of the DLL files and use it to replace the second one:

  1. Go to the Steam installation directory. It is usually in the path: C>Program Files (x86)> Steam > Bin.
  2. Right-click on the “Steamservice.dll” file and copy it.
  3. Go to “C>Program Files (x86)>Common Files> Steam” and paste the .dll file you copied. If prompted that the file already exists, opt to replace it by clicking the ‘Replace’ option.
  4. You can now launch your game and see if the error will still happen.

Fix 12: Delete Temporary Files

Deleting the temporary files that have been stored by your computer over time can help resolve the ‘VAC unable to verify game session’ error. The files might be corrupt. Follow these easy steps:

  1. Open the Run command by holding the Win key and pressing R.
  2. Type ‘%temp%’ in the text box and hit Enter or click the Ok button.
  3. Select all the items in the list by pressing Ctrl + A. Then press Shift + Delete to clear them.
  4. Click the Yes button to confirm the action if prompted.
  5. Launch Steam and see if the problem has been resolved.

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Fix 13: Update Your Drivers

It could be that you don’t have the correct device drivers installed on your computer. Running an update can help resolve driver issues that could be preventing your game from operating properly. We suggest using Auslogics Driver Updater to perform this task easily. The tool will automatically detect problematic drivers and install the correct versions provided by your device manufacturer. You won’t have to trouble yourself with finding out the specifications of your computer and sourcing the drivers yourself. Driver Updater will handle everything for you. Here’s what you have to do:

  1. Download and install Auslogics Driver Updater.
  2. Once the program has been installed, it will open automatically and detect the specifications of your computer, making sure to get the correct drivers.
  3. Click the ‘Scan Now’ button to begin locating faulty and outdated drivers.
  4. You can click the Update button beside the problematic drivers you want to update. Or you can click ‘Update All’ to fix all the detected drivers.
  5. Restart your computer after the update.

Note: You need the Pro version of Auslogics Driver Updater before you can download and install the updated version of your drivers.

Fix 14: Update Windows

Installing Windows updates removes vulnerabilities, updates your drivers, and fixes other issues that could be preventing your system and apps from functioning properly. It may be able to resolve the ‘VAC was unable to verify the game session’ error.

  1. Open the Settings app. To do this, hold the Windows key and press I.
  2. Click on Update & Security on the main page of the Settings app.
  3. Click on Windows Update displayed in the left pane of the new page that opens.
  4. Click on ‘Check for updates’ in the right pane. Wait for Windows to download and install the new updates, then restart your computer.

15: Turn Off Steam Beta

Some users reported fixing the issue by opting out of Steam’s Beta mode. Here’s how:

  1. Open Steam and sign in to your account.
  2. Click on the Steam tab and click on Settings from the menu that appears.
  3. Click on Account in the left pane.
  4. Click the ‘Change’ button under the ‘Beta participation’ section in the right pane.
  5. Select “NONE – Opt out of all Beta programs.”
  6. Click Ok to save the change. You can now check whether the problem has been resolved.

We hope you’ve found these tips on how to verify VAC in CSGO useful. You can share your comments, questions, or further suggestions in the comments section below.