: DLCs can be accidentally unchecked in the Steam Library under Properties > DLC.

The consequences of ignoring or bypassing this error vary depending on the type of missing content. If the missing DLC is a cosmetic item, such as a paint job or a cabin accessory, the game can usually "reset" the truck to a default state. However, if the missing content is a map expansion, the consequences are more severe. Loading a save without the required map data can cause the player’s truck to spawn in a non-existent coordinate, leading to an immediate crash to the desktop or the loss of all progress in that specific region.

Click . Wait for Steam to scan and redownload any missing data. 2. Force Reinstall DLCs