If you own a version (DVD or other digital retailer):
If your game has auto-updated to a newer version and you need to go back to 1.35 (often for mod compatibility), follow these steps from the official Steam community guide : Euro Truck Simulator 2 - Game Update V.1.35.1.31 - Download
Euro Truck Simulator 2 Update V.1.35.1.31 was a bridge between the "old" ETS2 and the modern powerhouse it is today. It brought DirectX 11 to the forefront, expanded the trailer economy, and refined the European landscape. Whether you are revisiting it for nostalgia or mod compatibility, it remains a testament to SCS Software's dedication to simulation excellence. If you own a version (DVD or other
If you are playing on Steam, the update should apply automatically. If your game hasn't updated yet: expanded the trailer economy