Finally, I found a software able to recover Firefox passwords !
But, yeah there’s a “but” : as this giveaway is only the “Basic Pro” version, you’ll need to disable FF master password if you have one !
It’s not a hassle, as you’ll just have to activate it again after the recovery & save.
There’s a hassle btw : this program doesn’t stop to remind you “buy premium version” everytime you use it. I hate that.
So, thanks, but uninstalled as soon I got my passwords list saved on disk.