Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

That's not supposed to happen; the Refresh should carry forward bookmarks, passwords, and your current session tabs (assuming it's not a private session). Documentation: Refresh Firefox - reset add-ons and settings. Sometimes the process stalls or gets interrupted, in which case, the data transfer can be very incomplete.

Were passwords the only data not carried forward?

Fred provided links to articles on key files for Firefox's password manager (logins.json and key3.db) that you may find in the old profile folder within the Old Firefox Data folder. If you have any questions about how best to restore those, please feel free to ask.

I refreshed Firefox earlier today and lost almost everything. I was able to restore my bookmarks from a backup taken earlier, but none of my passwords are saved. I can see the two files key3.dn and logins.json in the backups. I was able to copy logins to the current profile OK, but I don't have permissions to copy key3.

Please help, this is driving me mad!

I just checked and I am logged into Windows 10 as an administrator

And was able to copy the file over from the backup once I'd closed Firefix. However, even with these files in the current profile, saved passwords still don't show.

Make sure you Copy the needed files to the current profile.

Just to be sure, I just copied again with the same result. No saved logins or passwords.

Is it possible to restore the entire profile from the backup in Old Firefox Data?

You did copy both logins.json and key3.db files with Firefox closed that last time?

If you were running Firefox when you copied logins.json then it is likely that the file got changed.

I'm afraid you appear to be right. The date/timestamp on the files was after I ran the refresh, so they must have been overwritten. Presumably this happens each time you access firefox?

Looks like I'm going to have to reset each password as and when I use a site.

I understood the refresh process is supposed to restore everything automatically. If there a problem with this or did I just do things in the wrong order?

Did you copy logins.json and key3.db from the "Old Firefox Data" folder on the desktop to the current profile folder another time with Firefox closed?

That should bring back the passwords.