Use the Steam Beta system to get official, working version 1.37. Do not download from random websites.
If you try to load a save file from a newer version (e.g., 1.40 or higher) in 1.37, it will likely crash or corrupt the file. Use a dedicated profile for 1.37. Steam Workshop: euro truck simulator 2 version 137 download for pc work
This wasn't just a small patch; it introduced some of the most requested immersion features in the history of the game: The FMOD Sound Engine: Use the Steam Beta system to get official, working version 1