Your login email must be accessible for you to be able to reset or change the password login. If this is no longer accessible then all data sync will be deleted when you log back in with other devices.

The Primary Password (previously called the Master Password) is used as part of the encryption of your saved logins. If you lose this password, there is no way to decrypt the saved logins and you have to start from scratch. So obviously resetting is not helpful.

If you have been using Firefox Sync, your logins might be accessible from the Mozilla cloud as long as you know your Firefox Account password. Try this:

(1) Install the following add-on: https://addons.mozilla.org/firefox/addon/about-sync/

(2) Type or paste about:sync in the address bar and press Enter to load the extension page

(3) If you have Sync set to exchange logins and passwords, you should find a passwords section under "Collections" -- click Records (table) to see what is on the server.

The Primary Password is used to encrypt the encryption key stored in key4.db with an extra layer and there is no way to bypass it apart from having an older copy of key4.db file with no PP or with a known PP. If you would reset the PP then you will lose all logins stored in logins.json in the Firefox profile folder, so you may want to keep a backup of the current logins.json and key4.db in case you want to try again.

• https://support.mozilla.org/en-US/kb/reset-your-primary-password-if-youve-forgotten-it