AI Forces not showing up in "Create Game".

Level 2
Jul 25, 2017
Hi. I'm creating a game where it's just two melee AIs vs each other, and 8 other players are on their team, but they just play Heroes. I've set up the player properties and forces so that Red & Blue are AI, picked out their race, and they have buildings set up on the map already. When I go to the "create game" list, though, neither of the AI show up--they're all empty slots for players. I must be missing something, but I don't know what--maybe the fact that I started with an official melee map as the base has something to do with it. Is there a setting somewhere that allows me to switch to Use Custom Map Settings or something? I found one under Game Data Settings, but it didn't change anything. I have custom triggers and custom units placed on the map.