sudo apt-get autoremove appmenu-gtk appmenu-gtk3 appmen or sudo apt-get autoremove appmenu-gtk appmenu-gtk3 appmenu-qt.
I have used this command to remove the global menu in all installs of Unity. It works with all apps except Chrome and Firefox (even if you disable appropriate Add On in Firefox).
Any ideas how to fix this? I installed Unsetting, but that didn't work. Help!