Can't Load Saved Games

I am experiencing the same issue, with the following message.

This was in a solo game, playing a custom race on Windows 10

One thing that I did notice was, that I wanted to build the Galactic Trade Forum (Or how its called, the Unique Building), but instead of finishing it kinda failed and just hung in the production list for the rest of the play session. After it should have been finished but failed, it just went to the red bar look, that happens when others build something before you, and you can't catch up with the unique building anymore.

I thought that some other race muse have built it first then, but realized that I was able to choose the same building to build on other systems. When I clicked on it, it then started to build as usual and finished too, but the entry on the first building order did not disappear from the previous system that had the strange occurrence.

So yeah, maybe restarting the game will help with that, but turns out that I cannot load any of the savefiles that are from this gamesession anymore. Not the Autosaves, not the manual one.

If I can deliver any more information, I would be much obliged, I would love to continue the save that has issues here.

Cheers