Map Loading Issue

When I try and open a map, it goes to the "Generating Terrain" screen and when it loads all the way, it goes back to the map list menu where it shows your created maps. And then when I try and go back into that map or any others, it loads for half a second and then stops and doesn't load the map in. I end up having to exit and close the game, and then repeat the process about 3 or 4 times before it works and loads the map successfully.