Game does not load any save files

I'm playing on PC via Steam, with about 30 hours and, after completing the griffins' journey with Assan (no spoilers here), my PC simply shut down.

When I restart and open the game again, I can't open any of my saves. 

I get a message on the screen saying that the "request could not be processed". The problem is that this happens for all saves, not just the most recent one.

I'm trying to reinstall the game, but it really worries me that I'll have to start all over again! Has anyone else experienced something similar?