sounds like you deleted/moved your save folder...

what you need to do is remember where it was (hint: there is also a folder named 'Incomplete' in the same directory as your save folder was...you also need to remember exactly what its name was..then you have to make a new folder in the same directory and name it exactly the same way..

above advice is assuming that you have indeed done something with your saved folder...I've done it, and the above advice is the only way that I've ever been able to solve it...