At least it can be played in those eras. I have, in the past, made a couple of maps that can't usefully be played in *any* era.

Map 1: All mountains. The game starts fine, but of course, there's no place to build a city, so I end my turn. The enemy AI, of course, is in the same situation, so it gives up and disbands the starting settler. As a result, I am the only player left, and as a result, I win a Conquest victory. (I actually beat Sid difficulty this way, but I would argue that this doesn't count as an accomplishment.)

Map 2: All water. When trying to start the game, the game crashes with an error message to the effect of "can't fund enough starting locations". The game, of course, tries to find suitable places to place each civilization's starting settler, but is unable to because settlers can't be placed on water, and there are no non-water squares on the map, so the game has no choice but to give an error message. (IIRC, I think the editor warns you when you try to save the map that it might not work properly.)

(I should point out, however, that I was actively trying to break the game here, much like when I made my "no playable races" Morrowind mod, which surprisingly doesn't break Morrowind.)