I had the same issue and then I remembered this error when I first started using this mod. I was playing ETS2 in 64bit which ETS2MP won't work with (giving the same basic error). When I updated ETS2MP to the latest alpha, like many of you I kept receiving this error. What fixed the problem for me is I right clicked ETS2 from my Steam list and selected "Launch with DirectX". I started the game then I quite. After that I have had no problem launching ETS2MP. I hope this helps your issues as well.