Same here, game saving stopped work during gameplay with no error message.
Save dialog had been working as expected but game did not create any save in savegames folder for two hours and I was not able to make any new save any way I have tried. Any way to save current game stopped working. autosave, regular save, quick save, and even save and exit did not do anything, no new saves added.
After restarting game it started working again.
The only way to play broken crap like this is saving, saving and saving. Often. And even saving doesn't work.
