The BUG Scoreboard.py module which draws the scoreboard in a customizable grid format has a function to set which players are "waiting" for the current player to take their turn. When I originally wrote the code, I thought it put a * next to the current player (the opposite of what it actually does), so I called in setActive().
At some point I must have realized I had it backwards and changed the function to isWaiting(), but I forgot to change the place where it's called in CvMainInterface.py. Since this code is multiplayer-specific, it only fails there.