I'm in the boat with everyone else having the blank yield values. Before installing and starting my newest game I deleted the cache and moduserdata folders, in case that helps.
PS: To try and see if a reload would fix it, I quicksaved and directly quickloaded, which resulted in my unique building (the coffee house) not showing on the leader load screen and screwing up the tech tree, with no icons being there at all and all lines being over the place. I went back to the main menu and loaded my latest autosave created by the mod and the tech tree as well as leader load screen are fine, but still no city yields.
PPS: I also noticed that whenever I change which tile to work, the city changes its look on the map, like it would switch to another possible look, with the houses being arranged differently. In addition to that, if I change the city focus, my second city changes look like that, with the first staying the same. I currently only have two cities, so I don't know how it is with more than those.