If you own the game legally on Steam, you do not need to risk downloading random .zip files from untrusted third-party websites. Steam allows you to legally "roll back" your game version. Open your .

Right-click the downloaded American Truck Simulator V1.31.1s.zip and select “Extract to \American Truck Simulator V1.31.1s\”.

Right-click the downloaded American Truck Simulator V1.31.1s.zip file.

Install the Microsoft Visual C++ Redistributable packages corresponding to the game's release year.

The most important warning: The legitimate .zip file for V1.31.1s is not a standalone cracked game (piracy is illegal and dangerous). Instead, it is a game backup or a version rollback file used with a legitimate Steam copy.