Hi Sandman
I had the same problem as you about a week ago.
Did a reinstall keeping my game saves which made no difference.
On loading the saved game back to the Uplay screen.
I had to delete my game saves back to the start of the Baltic Operation before I could one to load.
I decided to update TWOS to 15 from 12 and start a new campaign.
No further problems to date.
I would suggest replacing your game launcher and then see if your existing saved games will load.
Uninstall from the Control Panel.
Your existing game launcher will have installed in C:\program files (x86)
This new one you can be installed on any drive and in any folder.
Hopefully that will do the trick?
Run it in administrator mode.
Post #157 How To Replace a Faulty SH5 Game Launcher
Peter