Reasons for the CSGO Vac was Unable to Verify Error

The error message “VAC was unable to verify your game session” can come up when you attempt to matchmake within the ‘Counter-Strike: Global Offensive’game. This error when occurs will not let you join the matchmaking process of the CS: GO game.

Reasons for the CSGO vac was unable to verify Error

You will get various reasons here for the occurrence of this error.

When the Steam client is not performing as it should, then there is a possibility for you to get this problem.
If the verification of CS: GO game files is not complete, then also you might encounter this error.
When the Steam client program files have got corrupted somehow, then this issue might crop up.
If the Windows OS is not up to date, then also you can face this issue.

Solutions to Fix this Issue

Here, there will be multiple methods that will help you to resolve the “VAC was unable to verify the game session CSGO” error.

Method 1: Start the Steam client once Again

If the Steam client has any kind of corruption within its program files, then there is a chance for you to get the “vac unable to verify game session” error message. Now, the correct answer to resolve this problem you will have to restart the Steam client once again. Get the steps here on how to do it.

First, locate the Steam icon on the desktop and double-click on it. This action will open the new window, in it, go to the upper left corner and choose the ‘Steam’ menu.
As soon as you click on that menu, then a drop-down list will appear. From that list, find the ‘Exit’ option and click on it.
Once you close the Steam client, next, open it again.
At this time click on the ‘Steam’ again and then choose the ‘Go Offline…’ option from the list that appears.
When a dialog box appears, next, click on the ‘Restart In Offline Mode’ button and wait for the Steam client to restart.
As the Steam client opens up in offline mode, then repeat the fourth step to get to the drop-down list of the Steam menu.
Now, from that menu, choose the ‘Go Online…’ option. When a new dialog box comes up, next, click on the ‘Restart And Go Online’ button.
Lastly, launch the CS: GO game and check if this error comes back or not.

Method 2: Steam client repair Procedure

If the Steam client does not perform as it should, then you can face this error. Now, the best solution to get rid of this issue is to repair the Steam client present within the computer. In order to do it, follow the steps below.

First, if the Steam client is open, then close it.
Now, click on the ‘Cortana’ logo to open the default search section of the Windows OS.
In that search section, type in the text ‘command prompt’ then from the search results panel locate the ‘Command Prompt’ option and right-click on it.
As soon as the popup list appears then click on the ‘Run as administrator’ option. This action will open up a new window having the title ‘Command Prompt’ along with the white text and black background will come up.
Inside that window type in the following command ‘ “C:\Program Files (x86)\Steam\bin\SteamService.exe” /repair’ and press the ‘Enter’ key to execute. The section of the command in double quotations represents the location of the Steam client.
Wait for the above command to complete the repair process of the Steam client. Once the execution is over, exit from the ‘Command Prompt’ window.
Finally, open the Steam client and then in it, run the game to see if this error reappears or not.

Method 3: Verification of the Game Files

If there is some integrity problem with the CS: GO game files, then for that cause you can even face this error. The best answer to resolve this problem you will have to inspect the game files of CS: GO present within the Steam client. For that to happen, follow the steps below.

First, launch the Steam client present within the computer. Next, inside the client window, click on the ‘Library’ menu.
This will open a page with a list full of all the games installed within the computer. Next, from that list, locate the CS: GO game and right-click on it.
When a popup menu appears, next, find and choose the ‘Properties’ option. As soon as you click on that option, then a new ‘Properties’ page will appear.
Inside that page, click on the ‘Local Files’ tab. Under this tab, locate and click on the ‘Verify Integrity Of Game Files’ button. This action will initiate the integrity verification process.
Once the checkup procedure is complete, next, the following message “All files successfully validated.” will appear. Next, click the ‘Close’ button to quit the ‘Properties’ page.
At last, open the game and then inspect if this problem comes up or not.

Install the CS: GO game once Again

If none of the methods presented here can resolve this error, then as the last solution, the only thing that you need is to remove and then reinstall the ‘Counter-Strike: Global Offensive’ game. To do that, follow the steps below.

First, go to method five and then follow the initial two steps to reveal the popup menu.
Next, from that menu locate and click on the ‘Uninstall…’ button. This action will open a new confirmation window.
Within the window, click on the ‘Delete’ button. As soon as you click on that button then the deletion process will start, so wait for it to complete.
Once the CS: GO game is removed, next, you will have to install it again within the Steam client.
To install the game you need to visit the store of the Steam client and follow the instructions on-screen instructions carefully.
Finally, check if this problem is present or not.