(Firefox Nightly) The tabs and menu buttons seem to have been relocated to a fixed pane on the bottom of the browser window. I can't tell if this was part of an update or some accidental swipe. My attempts to fix this: Longpressing these ui elements doesn't show any contextual options. Settings seems to only allow relocation of the url bar top/bottom. Nothing in the configuration editor (json or xml or whatever seems to cover this, but I am not particularly fluent in browser widgetspeak. Suffice it to say, tapping tabs and menu (for extensions) is a high frequency activity so having these irreversibly(?) relocated is frustrating.