VAC Was Unable to Verify the Game Session

Many CS: GO players face “VAC was unable to verify the game session” error. This is because of the integrity issue with the file system. Due to this, players are not able to queue matchmaking and unable to play matches. Valve develops VAC (Valve Anti-Cheat) as a component of the Steam platform; when the software detects any cheat on your system, it bans them in the future.

Possibly this may last for many weeks and days after the original detection. Players are kicked out if there is a flaw in the system’s memory or hardware. The information regarding the date of detection and type of cheat detected does not reveal to the user. VAC works on three different Operating Systems, which are Windows, macOS, and Linux. It uses Windows and Linux as its platform.

But, if you receive VAC Was Unable to Verify the Game Session error despite doing nothing wrong, it means there is a flaw with the configuration of files. Hence, this guide provides you with the fixes for this error. Begin with the first step and work your way down.

How to Fix VAC Was Unable to Verify the Game Session Error

These are the steps that can guide you to solve VAC Was Unable to Verify the Game Session error which you might be facing.

1. Running Steam As Administrator

To check whether Steam has administrator access on the system is the most basic step.

By default, Steam doesn’t have full administrator access, so to enjoy the optimal gaming experience, you need to give Steam full access. This means changing system configuration files and having a lot of resources and memory at its disposal.

You can grant Steam full administrative privileges and verify if the problem gets solved. First, you should make the Steam.exe file changes and later grant the whole Steam directory access.

2. Verifying Integrity of Game Files and Repairing Library

Games available in Steam are large files consisting of several GBs. There is a possibility that during the download/update, some of the data may have been corrupted. Steam has a feature within the client itself where integrity can be verified quite easily.

This functionality compares your downloaded version with that of the latest version present in the Steam server. Once this checking is done, it removes any unwanted files or updates them if required. Steam works efficiently and quickly since there are manifests present in each computer where a game is installed. Instead of checking the files one by one, Steam compares the manifests present on your PC with the one in the server.

The Steam library is where all your games are present, and you can only access them through it. So, you can also try repairing the Steam Library. It may be a possibility that the Steam library is not in the correct configuration. There may also be a case where you have installed Steam on one drive and your games on other. In that case, you have to repair both the libraries before relaunching your game.

There are some important things which you need to keep in mind. Due to large computations, this process takes a lot of time. Don’t cancel the process in between to avoid any further errors. Moreover, Steam can ask you to enter your credentials once it is done with the process. Don’t follow this step if you don’t have your account information at hand.

3. Power Cycling your Computer

Power cycling means turning off a computer completely and then turning it on again. Power cycling is done to reinitialize a set of configuration parameters or recover from an unresponsive state or module. It is also used to reset all the network configurations as they all are lost when you turn the laptop completely off.

The process of power cycling should be done properly. Firstly, shut down your laptop then remove all wires with proper care. After that, please remove the battery properly and detach it. Removal of the battery is necessary to ensure that all the capacitors are discharged correctly, and all the current data stored in RAM is left. Now, Press the Power button for 1 minute and then wait for 2-3 minutes before plugging the battery back in. After following all these steps, check if the problem got solved or not.

For PC, shut it down completely, disconnect all modules, and main power cable with proper care. Now, after waiting for the required time, set the computer to its original form, and check whether the error is solved or not.

4. Ending Steam Service

In some scenarios, Steam Services might already be running in the background due to which error is being triggered. So, to do so, follow the steps given below.

  • Select Windows+R to open the Run prompt.
  • Type in “Taskmgr” and click “Enter.
  • Select the “Processes” tab and select “Steam Service” inside it.
  • Click on the “End Task” button and close the task manager.
  • Verify if the flaw is detected or not.

5. Repairing Steam Client

If both of the above method fails, then there is a possibility that your Steam client is either corrupt or has some bad files. This can be fixed by executing a command on command line. This might require administrator privileges.

  • At first, Press Windows +S, type “cmd” in the dialogue box, right-click on the application, and click “Run as administrator“.
  • Once in elevated command prompt, execute the following command:

The path inside double inverted commas indicate the location of Steam on your computer. You can change it if your Steam file is elsewhere. This is just an illustration.

  • Wait for the process to finish. Then restart your system and check if the problem is solved or not.

6. Copying DLL File

Basically, there are two DLL Files present on your system, one of them is present in the Program Files and the other one resides in the Steam installation directory. In some cases, these files differ from each other due to which Steam is unable to verify your session. Hence, these steps will guide you to copy DLL files and replacing it.

  • Open the Steam installation directory.
  • Now, right-click on the “dll” file and select the “Copy” option from the menu.
  • Then, navigate to the following location.
  • Paste the “dll” file here and click on the “Replace” option if shown.
  • Launch Steam and try to start the game which you are trying to play.
  • Check if the problem is solved or not.

7. Deleting Temporary Files

Presence of some temporary files inside a system may cause an error. Here are some fixes which can help you in deleting such files.

  • Select Windows+R to open the run prompt.
  • Type in %temp% and press
  • Press Ctrl+A and Press Shift+Delete.
  • Click YES for deletion of temporary files.
  • Check if an issue persists or not.

8. Performing a File Repair

There are some cases where error occurs due to corruption in crucial Steam library files. Hence, here are some of the steps for performing a file repair.

  • Select Windows+R to open the Run prompt.
  • Type the given program inside a prompt.
  • Let the repair run and check to see if the flaws exists.
  • If there is no issue, navigate the following location.
  • Press Ctrl+A and delete everything permanently by selecting Shift + Delete.
  • Then navigate the following location.
  • Again, hold Ctrl+A to select everything in the folder and then press Shift+Delete to remove it.
  • Then, Steam will run and will download missing files.
  • Check if the error is detected or not.
  • If the error is not solved yet open Run prompt by pressing Windows+R.
  • Type in “Cmd” and press Shift+Ctrl+Enter to grant administrative privileges.
  • Execute the following commands by pressing Enter.
  • Check if the issue is still present.
  • If you still have the same error, type the following command which disables some of the security features which let VAC through and flaw is detected.

9. Checking for Background Services/Tasks

Some sources like VPN and other virtualization Softwares are the cause of this issue. VAC can flag you if you are running any of these.  So, these steps will guide us to stop the running of background services.

  • Press Windows+R to open the run prompt.
  • Type “service.msc” and press Enter to execute it.
  • In the service management window, right-click on any of the following and then disable it.
  • After that, open the Task Manager by pressing Ctrl+Alt+Del and then selecting Task Manager.
  • In the task manager, end the following processes if you notice them.
  • After this check, if the VAC was unable to verify the game session error persists or not.

10. Try some general fixes

Apart from the above-mentioned steps, here are some of the steps which can be followed to solve this error.

  • Try by restarting your Steam client properly. Go to Steam, change your username, and exit the client by clicking Steam > Exit. Now open Steam again goes to offline mode. Now go back online and check.
  • Make sure you have a proper running Network. Also, clear Steam, CS: GO, and other games from firewall restrictions to ensure they are not being blocked.
  • Check your antivirus software and other third-party programs. Make sure that there is no conflict with Steam.
  • Try to install DirectX.Net Framework, Microsoft Redistributable, and other key software again.
  • Try to change your profile name, close Steam, and check if that fixes the issue.
  • If you have idle master, close it and restart your PC. Now, verify if CS: GO works.
  • Try deleting your Config file or any key binds that you might have set.
  • If all of the above doesn’t work for you, try to back up the data and reinstall Steam completely.

11. Turn off Steam Beta

Sometimes Beta program can lead to problematic situations. So, here are some of the guide which will help you in solving errors caused by Beta.

  • Launch Steam and sign in to your account.
  • Select the Steam option on the top left and then click Settings.
  • Select Account in the left panel and then select Change option below the Beta Participation setting.
  • Select the None-Opt out of all Beta Programs
  • Save your settings and check to see if the issue remains.

12. Updating Windows

In some cases, the older or the outdated version can create problems and lead to risks and increases the percentage of failures. So, to save you from this situation, here are some of the steps to solve an issue.

  • Press Windows+I to open the settings.
  • Click on the Update & Security option and select Windows Update from the left panel.
  • Click on the Check for Updates option and wait for some time while Windows installs updates for you.
  • Check to see the issue remains after updating your computer.


We have tried to cover all the issues which most of you face while using Steam. There is no doubt that it comes with errors. But this version is the most promising one than the original.

Which remedy worked for you? Do not hesitate to give us feedback regarding this in the comment section below. Thank you so much for reading this. I hope it was helpful to you, and you were able to fix the flaw.