Help! How can I inactivate the "no town hall" message ?

I'm making a custom campaign in which I have created a completely knew techtree using only custom units. The problem is, though the map is not considered by the editor as a melee map, the game keeps telling me at game initialisation "you'll be showed to your opponents if you don't quickly build a town hall" (free translation from French, I hope you get what I mean, same message as when in a melee game you lose all your town halls). I could turn this out by giving my player a normal town hall I would hide using triggers, but I'm sure there is a more elegant solution. After all, you never get that ****ing message in all the commando type maps in which you have no town hall. Can someone help ?

Thanx, I'll try it.

I've done it and it works, it was the "enforce victory/defeat conditions for all players" trigger that created the problem, I had to create it by a trigger myself.