I am using Mozilla Firefox with the older version 28, because I do not like the newer Firefox versions…..
One day (April 2015) I noticed that the Evernote Web Clipper icon had disappeared from my Mozilla Firefox toolbar….
Web experts I could google had interesting ideas on problem cause and potential solotions — none worked for me.
Comparing my desktop PC with my notebook PC, I realized that one had installed Evernote Web Clipper Mozilla AddOn version 5.9.1 and the other version 6.x.x. – perhaps by automatic updating…
I switched back to Evernote Web Clipper 5.9.1 and my problem was solved.
Version 6 of the Evernotes Web Clipper is said to be a “complete re-write” – which was not good for my Firefox 28