I'm using Firefox ESR 45.4.0. I'm trying to access my development server (Django runserver) which only supports http, but Firefox now insists on rewriting http://dev.server.address/ to https:. I've been able access the dev server using http for years and years, but today, after trying to access my dev server when it wasn't running, which I think made Firefox try https instead of http when http failed, Firefox absolutely refuses to go back to http. I've set browser.urlbar.autoFill to false. I've set browser.urlbar.autoFill.typed to false. I've gone to the history bar and asked Firefox to forget about the server. Firefox still persists in rewriting http to https for this server, and I'm getting mightily frustrated.