I'm playing a game with the Altarians on an Immense galaxy against 17 opponents on the latest 4.2 version. Everything went fine until Turn 141 but then when I go to the next turn it gets stuck while processing the turn for Snathi Revenge. I even left it there for a few hours and it was still stuck on Snathi Revenge. So the AI triggered some kind of infinite loop condition I guess (I'm a programmer)
At first, I tried reloading and trying again but it did the same thing. Then I reloaded and declared war on the Snathi Revenge hoping to shake up whatever AI logic got stuck. And indeed then it was able to process the turn normally and for now, I'm unblocked, hopefully for good. However, that stuck condition is still an issue in general.
I am linking my save game from my OneDrive so that you can check it out here
(If there is an alternate preferred way of providing a save game, let me know and I'll upload it wherever)
Hope that you can figure this out,