[Phoenix-D]

"(waiting to be selected randomly as an AI race, and then set as "player race")"

You can't do that. If there isn't at least one human-controled race, the game ends. What you need to do is add a race, set it to human control. Then start the game, and go to the players menu. That will let you change any race from human to computer control, and vice versa. Set your original race to computer controled and the one you want to play to human controled.

Phoenix-D