I have done all the things stated above, as for the program to edit the height map...I did use GIMP I am unsure what they are using...but we are wanting to edit the map in game, to you know add objects and such. The only thing I have not done is just send the entire terrains folder, but the .zip file did include the folder in terrains with my map name, along with the height map, mask, textures, meshes and objects..
Many hours ago now, they did say that at one point, the game wasn't even allowing them to even open map maker anymore....