Hi, was it the Stop/Reload button? (The Stop/Reload button shows an X while the page is loading, and then a circling arrow after the page has finished loading.) If you removed that button from the toolbar, you should be able to re-add it from the Customize tab. More info on how to get in there: [[Customize Firefox controls, buttons and toolbars]]. Success? P.S. This forum does not accept email replies, so please follow up in your question here at: https://support.mozilla.org/questions/1419629