I was recording this weeks episodes last night when I ran into a nasty bug right after I recruited my 18th Hearthling into my little town. The game would become unstable and eventually crash to desktop, also if I tried to save the game with new game it would do nothing. If I tried to save with overwrite the save I overwrote would disappear.
Using an Old save I was able to consistently track it down to right after the daily update that gave me the 18th Hearthling.