When attempting to launch a Steam game, I am presented with the error message "Failed to start game (app already running)." What do I do?
This error is most commonly seen when launching a game that has closed improperly with a silent crash, or that is failing to launch properly.
Sometimes, the game may already be running under a different user account within your operating system.
In some cases, this error message will appear when there is an issue with the installation of a game. Complete the instructions as they are shown in the following link:
If the game is failing to launch correctly, or has silently crashed previously, you will need to contact the support team for that game to troubleshoot the crash/failure to launch.
When contacting the third-party support team for a game issue such as this, ensure that you click the blue "Problem with this game? Contact Support" button on the right side of the crashing game's Steam Support page to access the correct support site.
If you think there may be another user account on your computer that may be running this title, try logging out of all other user accounts, restarting your computer and testing the issue again.
If you are currently participating in the Steam beta, try opting out and testing the issue again.
Participants in the Steam beta programs should always test both the beta and normal versions of Steam when troubleshooting an issue.
For Windows computers, try the following:
The game should now be closed. You can try launching the title again, or proceed to other troubleshooting options.
If this fails, or Windows is having trouble closing the game with this method, try restarting your computer.
For other operating systems, try restarting your computer. Once your computer restarts, perform any troubleshooting operations that you intend before attempting to launch the game again.