Hai
Please follow this solution:
Have you tried verifying the integrity of your game files?
> Go to Steam Library
> Right click Euro Truck Simulator 2
> Properties
> Local Files
> Verify Integrity of Game Files
If the same error comes up again, please try to run the launcher as administrator.
If this doesn't help delete core_ets2mp.dll, re-open launcher and re-download file. Path: C:\ProgramData\TruckersMP.
Kind Regards,
Expectancy