I had Babylon and Sippar, both contributed to the holy site I was constructing in Babylon. I was in a war and just got Mycenge which was also constructing a holy site. In all cities now it says that it requires infinite time to complete a holy site (not sure which one). Furthermore if I press end turn at that point the game seems to get stuck: It's not frozen, I can load a game or quit, it just doesn't end the turn (I have waited several minutes). 

The zip file below contains the save game at that point and also the diagnostics file. 

Archive.zip

Thanks!