mentioned this a while back. think I found out when it happens.

it would appear only newly created empire factions are selectable as ai, if you try to select it in the same game session. (ie.. no exiting game)..

basically i made an empire a while back and i can't select it (to play against as ai). tried it again in beta with same faction and still no go. made another empire that's exactly the same aside from name/colors (Larood) ... that showed up.

exited game and went out to my doc/ (whatever path it was)... and deleted the 1st custom empire (if only interface in the game allows me to delete directly!) and start new game. the new empire faction is not selectable again as ai.

... exited.. copy/paste the custom empire and change the name (Sarood) ... neither selectable.

made another custom empire (Tijii) in the game and that one is selectable. exited game... not selectable again.

made yet another one, shows up in faction picker as ai. exit game. enter game and goes back to faction picker ... not available as ai.

beats me why.. nothing to do with race... tried human empire and quendor empire.. same thing happens.