It is necessary to have Steam running in order to play any game that has been downloaded. However, users have complained that they keep getting the “Failed to start game (app already running)” error while using CS:GO.
To avoid encountering this error again, our resident gamers listed all the methods in this guide:
How to Fix the Steam "App Already Running" Error
Fix #1: Close the Game Using Task Manager
This method will force your game to close if it has crashed silently or is “hanging.”
- To open Task Manager, hold down Ctrl+Shift+Esc.
- By clicking "More details," you can see all of the steps.
- Choose the tab for Processes.

- Find and choose the process that runs the game from the list. By expanding the Description column, you can get more information.
- Right-click on the process you want to end, and then click End task.
Fix #2: Opt-Out of the Current Steam Beta
If you’re in the Steam beta [1], you could try opting out to see if the error goes away.
- Click Steam in the upper left corner of Steam, then click Settings.
- Under Beta Participation on the Account tab, click the Change button.
- Choose NONE - Opt-out of all beta programs from the drop-down list and click Ok.
- You will be asked to start Steam up again. Click the button that says "Restart Steam."
Fix #3: Verify Integrity of the Game Files
If you get the “App Already Running” error after installing a new game on Steam, it’s likely that the game’s installation files were damaged or lost.
To fix this problem, you can use Steam’s built-in tool to check the integrity of a game’s files.

- Open Steam client.
- To see your games, click the Library tab.
- Then, right-click CS:GO and choose Properties.
- Go to the Local Files tab in the window that pops up.
- Then click the button that says "Verify the integrity of game files."
- Wait for Steam to check the files of the game.
- If a file fails the validation check, Steam will automatically get it again.
With these steps above, you should be able to get CS:GO running normally again.