I was trying to stop websites from reloading pages automatically so i setted: accessibility.blockautorefresh = true and browser.meta_refresh_when_inactive.disabled =true. Now many websites when loading , shows at the top of the page a notice: " Firefox prevented this page from automaticaly reloading ". In the older Firefox versions , it was an addon called: " Refresh blocker " which was automatically closing this notice after 5 to 60 seconds (depending on users preference). This addon does not exist now so , i wonder if there is a way to apply this setting using an other method , (maybe about:config modification , or other).