First of all, galaxy forge maps should only go in the Galaxy Forge folder, located in the same directory as that map designer folder you were putting them into. The map designer is basically a GUI for random maps, the Galaxy forge is a GUI for premade maps, you don't use them together.
Second, the most common cause of instant victories or defeats is not giving every player a starting planet. For every player make sure you actually selected a planet and change the owner/homeworld (if applicable) drop down boxes.
