FredBezies [1] filed a deletion request for firefox-extension-unmht [2]: Won't be usable with Mozilla Firefox 57.0+ ; not compatible with "Quantum" and WebExtensions : https://addons.mozilla.org/fr/firefox/addon/unmht/ "Not compatible with Firefox Quantum" [1] https://aur.archlinux.org/account/FredBezies/ [2] https://aur.archlinux.org/pkgbase/firefox-extension-unmht/