Microsoft Flight Simulator X players frequently get “Steam must be running to play this game” error message when they are launching the game in Windows 10. This error mostly occurs in newer Windows versions because the game is not given the necessary permissions by default so you need to do this manually.
If you don’t know how to do this, don’t worry, all you have to do is follow the steps below:
Fix 1: Run Microsoft Flight Simulator X as an Administrator
- Go to Steam library and type “Microsoft Flight Simulator X” in game search box.
- When it is listed, right-click on it and go to its Properties.
- On the left side of the Properties window, you will see several tabs. Click on “Local files” tab and then click “Browse Local Files” button.
- When you do this, you will see the folder where Microsoft Flight Simulator X is installed. Right-click on “fsx.exe” and open its Properties.
- Switch to “Compatibility” tab.
- There is a checkbox named “Run this program as an Administrator“. Enable it and click Apply.
- Restart Steam application.