Clippings worked sometimes. Very very often it does not! Instead of making a clipping you get the totally false message. ""Unable to retrieve text...""" or ""This page is currently busy. Wait...and try again"".
==>> It posts the 'page is currently busy' message when the page is NOT busy. The page is fully loaded and not busy. But the clippings ap just thinks the page is busy, when it is NOT!
I advise to save frustration and avoid installing clippings. Life is too short for frustrations and rage :(
The Mozilla team is rolling out a fix for Firefox which should resolve the certificate issue affecting all add-ons. See their Twitter feed for details: https://twitter.com/mozamo/status/1124627930301255680