By not working I'm assuming their game crashed upon trying to get into the map. Did they put everything into exports and the .sky into media>sky? Sometimes that's the only way it'll work. Though for whatever reason, sometimes .sky and .weather files crash maps.
If this isn't the issue, would it be too much of a bother to send me the map download via PM? I'll delete it once I'm done, however I'd like to see what's going where and if I can get it to work.