Ended up sieging out an enemy city, there were no defenders left when I decided to assault. The battle was quickly over, but the battle report only shows a blue bar, what I assume to be where the title is supposed to be written. I think I'm supposed to select what to do with the city? 

Since I can't progress the battle report, several other things have borked. The civics screen is empty, I can't click the al cities button, and I can't end turn.

Here's what it looks like: 

Reloading the save ended up in a stuck load. The save was reloadable after a restart though, and I could progress just fine.