There are a similar thread and support article which may help. https://support.mozilla.org/en-US/questions/1315684 https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#w_what-information-is-stored-in-my-profile

There is also a file named logins-backup.json which you can copy as logins.json if need be.

You should close Firefox before copying files or folders.

What about the rest of your profile? Settings, bookmarks, history, passwords . . . .

Try rebooting the computer.

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.