Taizun's post in Problem with log in into ETS2 MP in launcher was marked as the answer
You seem to be running the 32-bit version of ETS2, which is no longer supported.
Make sure your system is 64-bit, and make sure your game is launching in 64-bit mode. If your system is 32-bit, you will need to reinstall your system with the equivalent 64-bit version in order to play ETS2MP.
Taizun's post in Private server/session ? was marked as the answer
Private servers is not going to happen, it has been rejected many times before.
Please use the search-feature - searching for "private server" would have yielded these results:
Taizun's post in Can't open MP ETS2 was marked as the answer
Double-click ETS2 in Steam.
You should now get the following options:
Select "Play Euro Truck Simulator 2 (64-bit)".
If it is not available, or doesn't work, your system is most likely not 64-bit.
To make sure, please right-click "Computer" or "This PC" from your Start-menu and click "Properties".
What does it say next to "System type"?
If it says "32-bit", then you can not play TruckersMP, as only the 64-bit versions of ETS2 and ATS are supported. In that case you're going to need to reinstall your system as 64-bit.