If you encounter a site that does not work in Firefox, but works in another browser, then click the add-on button and follow the steps to report
Ma temmugreḍ-d asmel ur netteddu ara deg Firefox, maca itteddu deg yiminig-nniḍen, ihi sit ɣef tqeffalt n uzegrir tḍefreḍ imecwaṛen akken ad t-tazneḍ.