I had the same issue, here's what worked for me (in addition to deleting the save files like you did):
1. Press Window Key + R to get the Run dialogue box
2. Type %appdata% and hit OK
3. In the window that opened, go to the folder Renpy
4. Inside Renpy, find the folder Seven Kingdoms The Princess Problem and delete all the files inside it
That finally let me start totally fresh. Hope it works for you!