Hello, Please try these solution.
Access the Control Panel
Type "folder" into the search bar and select Show hidden files and folders.
Then, click on the View tab at the top of the window.
Under Advanced Settings, locate "Hidden files and folders." Select Show hidden files and folders just below that.
Click on apply and ok this window close.
Now go to Local Disk C > ProgramData > TruckersMP > data > ets2 > mod
In this directory, delete the .mp files.
Open TruckersMP in administrator mode.
F1 Press key and Click update button, little after update finished Launch ETS2.
Kind Regards,
KingModzv11