Double check that there is only one uLegionStandard in the object file. Try using civ.createUnit(object.uEvocatiFresh, object.tRomans,loser.location) This will tell us if the issue lies with civlua.createUnit, or something else. Actually, I think I just got it. The tile is currently occupied by the LegionStandard, which is owned by The Gods, and not the Romans. And, now, you're trying to create roman units on that tile before the Legion Standard has been deleted. civlua.createUnit mimics the old create unit event, which won't let you create units on tiles occupied by other tribes.