Hey, for some reason missions have dissapeared after the BeamNG update, I found a fix. Load any map affected by this bug and press F11 to open World Editor On the top menu go to Window -> Missions -> Mission Editor Click the green button next to the search bar and ensure only "Current Level Only" is selected. Go back to the misson editor and click File -> Reload Mission System Press F11 again to exit World Editor. That's should fix it.
Bump. This is a lifesaver. This actually happened to my vanilla maps as well, and the solution still works. Big thanks, since the alternative would be to reset my user data.