Maybe you had accidentally Caps Lock set. You can rename/remove key4.db and logins.json in the Firefox profile folder to reset the Primary Password and start with fresh files. If you have logins showing in logins.json then you may want to keep a backup copy of both files *https://support.mozilla.org/en-US/kb/reset-your-primary-password-if-youve-forgotten-it You can use the button on the "Help -> More Troubleshooting Information" (about:support) to go to the current Firefox profile folder or use the <b>about:profiles</b> page (Root directory). *Help -> More Troubleshooting Information -> Profile Folder/Directory:<br>Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder *https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data ----- You can can inspect the current login state and login and logout and change the Primary Password via the Security Device Manager. *Settings -> Privacy & Security<br>Security -> Certificates -> Security Devices In the left panel select "Software Security Device". You can find "Log In" and "Log Out" and "Change Password" in the very right panel.