1P extension in Firefox not opening

Hey iphoneuser,

Thank you for getting back to me.

The 1Password Classic extension was last updated in 2019. It was built on older technologies and will not be compatible with future updates to web browsers. Our modern extension, 1Password in the browser, is in active development: https://support.1password.com/getting-started-browser/

The latest version requires a membership and as you have suggested does not work with older standalone vaults. I recommend sending an email to our support team at support+tradein@1password.com so that they can look at how you're currently using 1Password and advise on the best way forward.