Right-click ATS in your Library > Properties > Installed Files > Verify integrity of game files . This fixes missing or corrupted data.
Once the download finishes, launch the game. You can verify the installation in two ways: american-truck-simulator-texas-installation-tutorail
Open and navigate to the American Truck Simulator store page. Scroll down to the Content For This Game section. Right-click ATS in your Library > Properties >
Before you can install the expansion, ensure the license is linked to your account: american-truck-simulator-texas-installation-tutorail