Obviously I (still!) don't know this mod's particulars, but that kind of crash often indicates that one of the AI-Civs is trying to do something illegal, such as unloading an 'Immobile' unit from a ship onto a non-city land-tile.
Or (if the game allows Settler-type units to be built), there may be a 'houseboat' somewhere on the map (i.e. a naval transport unit with a Settler aboard, belonging to an AI-Civ which just lost its last city): the game is trying to eliminate the AI, but failing because that AI still has a surviving pop-point.
Or it might simply be that the mod is so huge, that the engine is taking its own sweet time making all the necessary end-of-turn calculations of trade routes, etc.* On Huge+ maps with a full 31 Civs, this can sometimes take a looong time -- so it may look like the game has crashed, but if you let it sit for a while, it will eventually finish.
*(The Civ3 executable began development in the very late 90s, when players would mostly still be using single-core processors -- so a modern multicore machine may not significantly speed up the interturn processing).
Like I said before, though, you'd be much better advised posting/moving this question somewhere folks familiar with the mod are more likely to see it.
