Here's what happens for me when I try to load a URL that doesn't exist: 1. Say I start with a page loaded, like 'mozilla.org'. 2. Now I click the address bar, type and address that doesn't exist, such as 'foobar123.org', and press enter. 3. After a brief animation of the progress bar, the original site, 'mozilla.org', remains loaded. There is no indication that I tried and failed to load a site (i.e. no "Server not found" message like on desktop), and no indication of what that site was (i.e. the address bar still shows the title of 'mozilla.org'). 4. Worse, if I click on the address bar the address in there is 'mozilla.org', and not what I last typed ('foobar123.org'). This means that if I just laboriously typed in a long URL, and the reason it couldn't be loaded is that there was a typo in it - I now have to start typing it from scratch! I believe this UX can be improved considerably. Specifically: 1. Don't go back to showing the old page. Show a "Server not found" or "Page not found" page, like on desktop. The page should include the URL I tried to load. 2. When clicking on the address bar, the address in there should be the one I tried to load, so that if there's a typo in there I can correct it easily and re-try.
This is also fixed in latest Gaia - thanks!