''mdhilliard [[#question-1279551|said]]'' <blockquote> The Adobe Acrobat extension is not present. Why? </blockquote> Could you try doing a normal Firefox exit and start it up again to see whether Firefox rediscovers the extension in a new location? Here's why I suggest that first: Starting in Firefox 74, extensions like the Adobe Acrobat Create PDF extension that are advertised to Firefox through the Windows Registry -- called sideloading -- will be ignored. In preparation, Firefox 73 is supposed to copy the extension into a Firefox folder. It is '''not''' supposed to get lost completely. But maybe it takes a couple of tries. ''Ref.'' https://blog.mozilla.org/addons/2019/10/31/firefox-to-discontinue-sideloaded-extensions/