FIX: VAC Was Unable to Verify Your Game Session

If you're reading this, you've probably received the following error: "Matchmaking Failed - VAC was unable to verify your game session". We've got some good news, and some even better news for you. The good news? You haven't been VAC banned! The better news? There's an easy fix that works in 2019!

As of a recent Windows 10 update (September 2019), it may be necessary to run Steam and CS:GO as administrator until Steam resolve the conflict. Please try this before and after running the below three fixes.
To do this: close Steam, run Steam as administrator (right click > "Run as administrator"), then opening CS:GO as administrator (right click > "Run as administrator").

Fix #1, which is outlined below, works for about 95% of people, so chances are it will work and solve your error. In the unlikely case that it doesn't, we've provided some other fixes that definitely will!

Fix #1: Verify Integrity of Game Files and Restart PC

To perform this fix, open up Steam, go to Library, right click Counter Strike: Global Offensive, and then click "Properties":

After opening up the properties window, head to "Local Files" and click "Verify Integrity of Game Files":

Wait for this to complete, and then restart your computer.

After completing the above, your CS:GO should be working fine, and the "Matchmaking Failed - VAC was unable to verify your game session" error should be gone. If, however, it's still occurring, continue reading Fix #2 below.

Fix #2: Repair the Steam Service

Repairing the Steam service is recommended by Valve here. To do this, all you need to do is:

Close Steam. Do this by right clicking Steam in your System Tray (bottom right hand corner) and clicking "Exit":

Open your Start Menu, search for "Run" and open the file named "Run":

Enter the following into the text box and press "OK":

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

An empty terminal should then pop up. Wait for this to close and re-open Steam - your issue should be fixed.

If your error isn't fixed, continue reading for Fix #3.

Fix #3: Completely Reinstall CS:GO

If the two fixes outlined above haven't worked, your issue is likely one that won't be resolved by changing a setting or restarting your computer. Whilst we recommend you search the web to see if there is anything else that might work for you, chances are, you're going to save time by reinstalling CS:GO. Reinstalling the game will get the issue fixed quickly, and will save you having to try lots of different fixes (that probably won't work).

To reinstall CS:GO completely, go to your Library in Steam, right click "Counter-Strike: Global Offensive" and click "Uninstall":

On the window that pops up, click "Delete":

Then you'll need to reinstall CS:GO. You can do this at https://store.steampowered.com/app/730/CounterStrike_Global_Offensive/. After reinstalling CS:GO, the "Matchmaking Failed - VAC was unable to verify your game session" error should be fixed!

If you're still experiencing issues after trying all of the above three fixes, send us a Tweet @Total_CSGO and we'll do our best to help!

If you play Roblox and you're experiencing issues with your game, check out these Roblox error guides for help.