Those who use the latest version of Firefox (66.6) may have noticed that their usual extensions have disappeared. This is due to a bug in this browser in which an expired certificate gives the impression that all of these add-ons are corrupt. Mozilla has stated that a fix is being rolled out at present.
https://www.notebookcheck.net/Firefox-affected-by-bug-that-disables-all-the-browser-s-extensions.420157.0.html
InconvenienceP No they just flat broke Firefox. They don't even have native an mhtml or pdf save capability.
I don't see this as a bug as much as a really poor decision made by Firefox to require certificate authentication for all add-ons at times after time of install. I get why they include certificate authentication, as that cuts down on malware. But requiring certificates to check in after the extension has already been installed? Bad form, Firefox.