In the event that the passwords information is lost, you should record all information in a separate text file somewhere else on your hard drive, or written down. You can easily copy and paste if you need to do so. If you are concerned about someone else looking at that file, you can compress it using a password.

I called for help about your sync.

What about your other devices, are the passwords still there?

Is anything else missing from your settings?

You would need an older copy of the logins.json and key3.db files to recover lost passwords.

You can check in Windows Explorer if there is a previous version of these two files available as part of a system restore point.

• right-click: Properties -> Previous Versions

Do you have an "Old Firefox Data" folder on the desktop in case the Refresh feature in Firefox has been used and a new profile has been created?

• https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems
• https://support.mozilla.org/en-US/kb/Recovering+important+data+from+an+old+profile