Sometimes, I cannot select any unit until I go into a city and change it's production. I have no idea where this is coming from, but I play on custom maps made in world builder, and haven't seen this happen otherwise. I suspect it may be more of an issue of the map being huge, very crowded, and very laggy. So much so I've had to tune down all of my settings. I don't usually play games well into the future, past the "One More Turn" index, but doing so has been a useful learning experience. (I'm on Turn 685, 2017 in an Epic Game) Just wondering if anyone has ever had this happen to them. (Only Mod I am currently using is Removable Districts) It doesn't happen often, just once in a while.