Reproduction Start with two existing html pages. I’ve set up a demo linked at the bottom but it’s pretty simple. Page 1 which links to page 2 Page 2 which links to a page that will never load. Open page 1. Tap on the link to page 2. Tap on the link to page 3. The browser now shows a page load error and the url of the page that failed to load. Expected result Pressing the back button navigates to page 2. Actual result Pressing the back button navigates to page 1. http://robert-lamont.co.uk/firefox-focus-navigation-bug/