It appear the latest update might have bricked the main program. I now get the following message pop up and can't access 1Password: "You’ve used a newer version of 1Password on this device. Update to the latest version to keep using 1Password. Contact mailto:support@1password.com if you need help." There appears to be a Feb 2022 solution to a similar Mac issue at that time, but not one for Windows. If a similar Windows fix could be provided, that would be great. Interestingly, despite the pop up, the Firefox browser extension still works.

1Password Version: Latest?
Extension Version: 2.6.0
OS Version: Windows 10
Browser:_ Firefox