Oh yeah, I totally misread your original comment. You are correct!
Missions require at least some locations to be revealed (the more the better). If you do have locations revealed but roll an invalid location type (as in it doesn't exist on your map), you are to roll again until a valid location results. Alternatively you can place the location based on the distance given for the mission to start doing the missions right away. I typically have new players explore the map a bit doing Contracts before taking on Missions as it helps to fill-in the map.