Firefox can even break itself. If you deselect "View -> Toolbars -> Menu Bar" with the menu bar then the menu bar disappears. How do you get it back? You can

Firefox can even break itself. If you deselect "View -> Toolbars -> Menu Bar" with the menu bar then the menu bar disappears. How do you get it back? You can't repeat the same procedure because the menu bar is not there any more! It turns out you can right-click on an empty space on the tab bar to reenable the menu bar, but this is far from obvious.