Hello dear @w1ldthing,
"This Guide is for ATS and/or ETS2.
1. Locate and Secure your Profiles, Copy them to a seperate Folder.
ATS: http://prntscr.com/f7ofiu
ETS: http://prntscr.com/f6bney
2. Then de-install ATS/ETS2 via Steam and de- install TruckersMP.
3. Restart your PC.
4. Then start searching for all old Folders of TruckersMP and ATS/ETS2 and Delete them. A RegCleaner Software will be helpfull. Sometimes there are "Dumb" Folders/Paths to ATS/ETS2, that were created by the TruckersMP Launcher.
http://prntscr.com/hommq6
http://prntscr.com/hommzm
http://prntscr.com/homn7x
5. When u deleted all Folders, Restart ur PC Again.
6. Log In to Steam-->Rightclick on Steam--->Settings-->Download-->Steam Library Folders-->Add Library Folder---->Choose another Partition or Hdd and mark it as Default Library.
http://prntscr.com/homntm
http://prntscr.com/homozx
7. After that Procedure, Re- Install ATS/ETS2 via Steam into the new Library, make sure you installing this Version.
ETS: http://prntscr.com/f7nmne
ATS: http://prntscr.com/f85fz
important: Check TruckersMP for the actual Versions of the Game, they can be different!!
8. Start the Game in Single Player and check the Version. Create a new Profile, but do not Drive. Close the Game.
9. Search with Windows File Explorer the Path to the ETS/ATS Installation. Keep this Path in Mind.
After that, download the actual Version of TruckersMP, unpack it to a seperate Folder. Install it from this Folder as Administrator.
Make sure that you having the right Path to the Games when you Installing TruckersMP.
You have to check them manually, do not let the Launcher Auto searching for them.
10. After the Installation start the Launcher as Administrator and let him finishing his Downloads. Then start the Multiplayer. If you can Play, close the Game and insert your old Game Pofiles." quote - RequieB Janurary, 17th
I hope that helps.