Found the problem: the upgrade to FF57 uninstalled the plugin "Master Password+" as being not compatable with FF57. Uninstalling this plugin also discarded ALL my login credentials! Thank you Mozilla!

How is it Mozilla fault the Addon isn't updated by the creators? Your placing the blame in the wrong camp.

You should have downgraded to a prior Firefox, got the information you needed, then decide to upgrade or not.

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.

FredMcD, thanks for the tip, but it shouldn't be needed.

I was using a plugin because FF fails to improve the usability of the Master Password pop-up. First the user gets a pop-up asking for a password for the Sofware Security Device. What is a Software Security Device? No indication at all that this is coming from Firefox! Secondly this pop-up takes input focus always at an unexpected and inconvenient moment making me typing an URL in the password field.

So FF is forcing me to use a plugin to solve a problem that Mozilla is not adressing. Of course this nice guy that shared his solution is not on top of every FF update. Therefor I blame Mozilla for losing my login credentials!

Hi peerv, do you still know your old master password? If so, you may be able to dig up some backup copies of your login-related files and use them.

If you aren't in the habit of making backups of your Firefox profile folder (presumably as part of a system backup), Windows may have captured a copy in a restore point when doing monthly updates. That is difficult to access on Windows 8-10, but there is a third party utility program you could try:

(1) Set Windows to show hidden files and folders: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

(2) Download this program: http://nicbedford.co.uk/software/systemrestoreexplorer/

When you run System Restore Explorer, it will show available restore points. Pick one, and follow this path:

\Users\username\AppData\Roaming\Mozilla\Firefox\Profiles

Here you may find one or multiple profile folders. Hopefully the modification dates will help you determine which is most up-to-date in that case.

Inside the folder, find these files and copy them out to a neutral location such as your Documents folder (your "live" Documents folder, not the Documents folder in the restore point):

• logins.json
• key3.db

Later, you can exit out of Firefox and replace the current files (presumably zapped by resetting the master password) with the older ones. That swap would be made in your currently active profile folder. More info on accessing that folder in this article: Profiles - Where Firefox stores your bookmarks, passwords and other user data.

One other thought: a Master Password is purely a local security measure. It can be different on every device because Sync does not synchronize your master password. Therefore, it might be possible to re-download your logins from Sync to populate a new logins.json and key3.db file pair. I'm not sure of the safest way to do that, i.e., without wiping out logins in the Sync account and other connected devices. Hopefully a Sync guru will have a suggestion.

Thanks, fortunately I had a laptop which I hadn't used for a while. FF on this laptop did not upgrade yet to FF57. Luckely I could recover my login credentials from this laptop.

Great news, thanks for the update.

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.