Game ends at turn zero

I tried setting up an AI only battle involving 34 civs, however, upon initialising the game, no units (i.e. settler and warrior) are apparent and the entire map is fog of war. A few seconds later the game ends with the "You have been defeated" screen. What could be causing this?

Mods:

• 43 Civ DLL
• Info Addict
• In-Game Editor

Game Setup:

• Spectating as Venice
• 34 Civs (excluding the spectator), no modded civs, no teams, no city-states
• Immortal difficulty with standard game pace
• Huge Terra map (I suspect this may be the problem)
• Domination victory exclusive