I'd first try generating a new def file on the ProMods website. The one you have currently includes support for the Special Transport DLC, but TruckersMP doesn't support this, so there could be an issue with that.
You could also try creating a fresh profile, as it's possible you've used some other mods on single player, and they've caused that profile to not work without them.
If that doesn't work, I'd suggest removing the Middle East addon, so then you'll know if the issue is with that, or the base ProMods addon.
If it still won't launch, then I'd suggest removing all the ProMods files, and downloading them fresh from the ProMods website.