Save file contains unrecognised additional data

Hello,
played my original game through Lucas' launcher. Saving, going to the main menu and loading save worked fine. But when I closed the game, next day in the main menu Load save screen, Save1 shows L0 M0, and a warning pops up. How can I recover and use my saved game? I only finished Level 1 on it, but not being able to save progress means i can't complete it. Thanks in advance!

Can you upload your save file to a file sharing site and link it to me? I'll have a look to see if it's recoverable

Thanks,
Josh

www.dropbox.com/scl/fi/a11fkubmkcb1uscmddv3u/Save1?rlkey=7ds7lbdhloo7pjdk3oe47ce29&dl=0

There you go. Thank you for taking the time!

I can certainly say that is... not recoverable. There's seemingly no data in the save file what so ever.