Signs of Corruption

This just happened to me last night and I can't remember the last time I've had the household thumbnail disappear. The save loads fine (no tents in WA chest). I'm not sure what's causing this but it could be because of such a large household (12). I've been told on tumblr by a few people that they also have had this happen but the save continue to work just fine. So far, that's been my experience too.
https://78.media.tumblr.com/2c0a45728e6d10e2244498a215142146/tumblr_p48as8rKRM1ssiu0eo1_1280.png