I was sent down the same uninstall/re-install rabbit hole with a few new suggestions to try the latest beta versions of the app and extension. Unfortunately, this new info didn't yield any new results. Reading manifest: Warning processing key: An unexpected property was found in the WebExtension manifest. I noticed that when debugging the extension (Menu > Add-ons > Extensions (click settings icon) > Debug Add-ons) Firefox was showing a warning: This weekend, I found myself with some free time and decided to see if I could get to the bottom of the issue. This was a minor inconvenience but because the 1Password desktop app was still working fine and I didn't want to waste any more time trying to fix it, I let it be. When the classic uninstall/re-install advice from 1Password didn't resolve the issue and a few quick searches on Google also proved fruitless, I gave up. Clicking on the extension icon did nothing and selecting login fields on webpages no longer showed 1Password suggestions. Then, about 4 or so weeks ago the Firefox extension for 1Password just stopped working. The switch went great and everything worked well. 1Password Firefox extension not working - solved!

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