See, that's the weird thing. In making the mod, I just copied the entire directory of RFRE into my new mod directory, so the files that are there should be the same files that the makes of RFRE used, and thus they should work. It is this that makes this problem so weird. I have, last night, made even a triple check, and yet nothing seems to be wrong.
So I don't know.
EDIT
Is it possible that having two or more of the leaderheads as the same file could cause such a problem? I have a few that are the same file, because their unique race's all were Greek descent, so I used one that was Greek. I checked and put every civ's servus unit in my territory and contacted each of them to see which were working and which were not. Most didn't, but after a while, the game just has an error occur, and crashes the game.
It just gets weirder and weirder.