When I tried the save made after the game hung, the turn continued normally without a problem.
However, when I tried the save that is one turn before the game hung, strange things happened. This is the save that ends in T277 that I gave all the steps for. I got a notice that Porter M1-1 was being launched empty. As I went through things I saw that the ship AST Selenta M4-2 just to the right of the shipyard at Reverie II was invisible when I was zoomed in but had an icon when I was zoomed out. When I clicked on Details, I was shown the details of the fleet that was on top the shipyard. This fleet also contained the same ship, AST Selenta M4-3, which was visible instead of invisible.
The next idle ship was shown at the planet Astera. It was also invisible when zoomed in and had an icon when zoomed out. Clicking on Details gave the details of the same ship, but it was on top of the shipyard and visible.
I was able to move any one, but only one, of the duplicate ships. When one was moved the moves of the other were also used up.
I decided to decommission the invisible version of the ship AST Selenta M4-3 to see what would happen. The visible one vanished. When I clicked on the invisible one, the game crashed to desktop. I think a crash report was automatically sent in. I referenced this post in the comments section of the report.
Maybe a bug still exists, or maybe trying a save made with the previous version is cause. I'll the devs figure it out.