Here's a link about managing add ons in Firefox. I can't guess what you have there.
Read https://support.mozilla.org/en-US/kb/disable-or-remove-add-ons
You don't have to remove them at first. Just disable until you find Waldo.
When navigating any web page with my cursor, every URL the cursor touches brings up the full URL address, sometime blocking images or copy that I want to see. How can this feature, probably intended as a security measure, be eliminated?

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