Storage file is corrupted

My Client has a problem with his save file he saved as he normally does unfortunately he replaces old save files every time.
when he tries to open his save file it says
“not compatible with this application”
so I tried to decrypt his file using xls padlock and I received this message
Storage file is corrupted or is not compatible with the selected Excel workbook / application. Cannot continue.
what can I do this is very important to him he worked for 2 weeks on this .

This means that you probably released a new EXE file with updated Application GUID and/or Application Secret Key. Have you made backups of your previous XLS Padlock project files?