No, no other mods, nothing in custom assets. DirectIP connection between two computers on my local LAN. I hit End Turn, End Turn, End Turn, and then the units on a city were selected (what I assume is what you meant by going to a city view, though it didn't actually zoom me into the city), at which point I selected the warrior in that stack and upgraded him to a Pikeman.
Nothing happened, so I ended turn, had the Incans upgrade a Quachwa to a Pikeman, ended turn, inserted a castle into the production stream in that Mayan city, ended turn, and at that point called it a night.