That's a new feature in Firefox 43. To turn it off do this:

1. Go to about:config in Firefox
2. Click the I'll be careful button
3. Locate the browser.urlbar.unifiedcomplete boolean
4. Change the value to false

Note: You may need to restart Firefox for the changes to take effect.

Hi alfieg, that top item is for your information: it describes what is going to happen if you press Enter or click the Go button.

• If there are no spaces in what you typed, usually that first row will show where "autofill" will take you if you press Enter or click Go.
• If there are spaces in what you typed, that first row will show what search engine will be used if you press Enter or click Go.

If you want to skip over that and use the first suggested site from history or bookmarks, it is still one down-arrow-press from where you are typing.

Now... from what you're seeing when you type firefox I think you have set these to false in about:config:

• browser.urlbar.autoFill
• keyword.enabled

With those changes or without them, you can remove that top line in two ways:

(1) Roll back the changes to the bar using a preference — as the-edmeister described

This prevents Firefox from showing search engine suggestions on the bar, so for anyone wanting to display those, this would not be a good approach.

(2) Hide the top line of the bar using a custom style rule

You can apply custom style rules to Firefox's user interface using either the Stylish extension or a userChrome.css file. For example, here's a rule that will do the trick:

 @namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);  #PopupAutoCompleteRichResult richlistitem[type*="heuristic"] {    display:none !important;  }

If you prefer this approach, we could spell out the steps in more detail, but I suspect you aren't interested in search suggestions on the drop-down.

the-edmeister: This is exactly what it was, and why I wasn't able to solve this on my own...a new feature. I have successfully turned it off as per your instructions. Thank you.

jscher2000, that's the way I had set it. I had that turned off a long time ago, and it wasn't that. By following the-edmeister's instructions, the URL bar performed exactly the way I had set it before the Firefox 43 update.

Is the custom style rule the same way as the ed-meister's simple instructions or is it something different?

Yes, I understand your settings, I've been there myself (although now I have keyword enabled). Your settings do not cause the extra line to appear, but they made the line especially uninformative for you.

The custom style rule needs to be applied to Firefox using either the Stylish extension or a userChrome.css file. Then it hides that top item without changing anything else. Sometimes settings like the one you changed are temporary/transitional and eventually go away as the code is finalized and streamlined. So the style rule approach might be necessary later, but it sounds as though you won't need it for now.

(Comment deleted on reconsideration after further testing. I like the chosen solution. It works great.)