Sorry @BITbOY I’ve just saw your file and it’s full of null bytes. Other people on Windows 10 experienced this issue too with a possible solution. Where you saving the file in a USB driver? or your personal disk? could you please do a check disk?
Anyway at this moment the file cannot be recovered. I’m thinking for the future some possibles ways to avoid this. For example: 1) reopen the file to validate that it was correctly saved, 2) don’t destroy the sessions data when the program is closed so we can recover old sprites in these special cases.