Did you check to see if those addons work with the latest version of FF? Addon issues aren't a FF end user help to fix that is for the addon creator to provide support for.

Is there a resolution to the issue of One Note Clipper? I used this a great deal on Chrome - while I like Firefox, this may be a the deal breaker for me

Hello Pete and Hello Della,

As for OneNote Web Clipper : would you please ask the developer(s) - see under "More information" => Support Email

https://addons.mozilla.org/en-US/firefox/addon/onenote-clipper/

And the same for Evernote Web Clipper : under more "More information" => Support Site.

https://addons.mozilla.org/en-US/firefox/addon/evernote-web-clipper/

Also see : https://help.evernote.com/hc/en-us