It is a bug for your earliest hunter units since the settings as are only allow 2 promotions before you reach the limit and tyhe promotion to go beyond that requires two promotions so you can't get it and go beyond... Not a problem later on and yes the Hunter Review will fix the problem for hunter line units. I'll look into them. Some building costs seem a bit off still. If a building is showing in tech X but requires a later tech as well. Is it getting the cost from the tech with the highest column number? Example is Hydro insisted that a number of buildings show up in the Shelter Building tech on the tech tree but you can't build them until you get a much later tech. These buildings should be getting the cost from the later techs not shelter building. Early religion buildings are still a bit off but I think I can fix that mostly. In standard BtS the cost and tech the buildings show is defined via the special building tag. All we need do is have a new set of special buildings for the early religions eg all temple level buildings at Animism, temple 2 (monastery) at ?? and cathedral at ???.