I think this is a bug. I have multiple level 2 cities, but I can only build a Hedge Wall in some of them. I have the necessary resources, but in some of my cities the button to build a Hedge Wall is greyed out, even though none of the resource requirements are listed in red. In other cities, the button is selectable.
Playing in 1.05, but it was a game I started in 1.01 (not sure if that matters).
