There's an unreleased (as in the patch isn't released) changelog https://forums.galciv4.com/513629/page/1/#3858937 that has the fix for this in it. I don't know when it'll go onto the test branch, but it's coming.

edit: V As Derek said.

This will be fixed in the 1.05 update.

I can report that the 1.05 test version no longer hangs up with the save I submitted aka the bug appears fixed to me.   Also, the turns in general are resolving MUCH faster than they used to.   I don't know if that it because there were other situations where the same problem wasn't hanging the game up, but was slowing it down and I couldn't see them, but whatever the case it's much better now.

Unfortunately, I think there might be some kind of memory leak in 1.05 test as my game seemed to become lethargic after about 3 hours of continuous playing.   This was not the same issue I had before.    Everything slowed down.   Even bringing up the menus was slow.  Probably not a show stopper, but something to look at.

Hm, I'm seeing something similar. This morning, the game seemed a bunch faster last night after I had played for a long while, particularily during proccessing the next turn and the autosave takes a while and the lag is noticeable when I complete a research and select a new one, the window comes up during the autosave phase and I had significant lag last night where it would take a while to close after clicking done, while there was no noticeable lag. Even saved when a research was about to complete, shut down computer to clear cache and whatever to be sure, and it was definetly faster. I'll try to observe when it starts getting slow.

Should create a new thread for this though.

Go for it if you want or let me know.