After having lost my bookmarks and personal information in a previous Firefox version (it kept telling me the file was in use by some other application), I managed to restore them. Now I am using 74.0 and I want to import my user certificate, from a backup created with the previous version of Firefox, in a .p12 file, but it won't appear as an option. Even if I choose to see all files and select the backup file, nothing happens, just as if it was empty. But I get no error message.