Musecore 4: Recovery of an automatic backup in windows notepad version

Hi there,
My musecore 4 just crashed and I lost a part of my work.
I founded a recent file in %localappdata% and find the last backup, but it's in windows note pad version.
This is weird cause in my musecore 3 file, the backups are in musecore 4 version.
I can't open the windowns note pad versions with musecore, and when I open it in note pad, it don't work.
Anyone can help me?

Thanks :)