Nice, helpful FF Addon although it routinely marks a Folder of my Firefox 60 Addons as "All Broken". They All work perfectly. Addon/Save temporarily Removes Red Dot but Next Scan produces same, Incorrect Broken tag.
Manual Deletes a Must as Other Broken Errors exist that may Delete Desired Bookmarks.

All below Work - Show Broken ---
Examples: (uBlock Origin) https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/?src=userprofile
(ByPass Paywalls Addon): https://addons.mozilla.org/en-US/firefox/user/anonymous-73cab9766f91fbcf6e3341c17014380e/
(Text Multi-Copy Addon) https://addons.mozilla.org/en-US/firefox/addon/text-multicopy/?src=ss


Shows Always as Broken. It works as all others do.