Ok, I don't know for sure, if it will work, but please try all of this:
Install latest version of graphics card driver/Windows updates
Try to run Euro Truck Simulator 2 in OpenGL Mode. To do this, you have to start the game on steam and do this:
and click play!
Now load your profile and save it! Exit the game. Try to play multiplayer and see if it fixed the problem.
If nothing help, then please try to create a new profile without mods and try to play multiplayer with that new profile!
If it crashes again after you've tried all of the steps above, please send me the new game.log and tell us what Windows version you have!
I hope it helps and works!