Nautilus menu bar missing in Ubuntu 18.04

Solution 1:

The menu bar does not exist any more indeed. Menu bars are deprecated in Gnome. This is reflected in all Gnome applications, except gnome-terminal, shipping without a menu bar.

• Many actions you do with specific items (aka files and folders) are available through the right-click menu
• The hamburger menu provides options with respect to the view
• The application menu, in the top bar of Gnome Shell, displays application wide options.

Like it or not, this is how the Gnome developers see software evolving. If you do not want to adapt to this vision, there are still a plethora of alternative desktops where the "traditional" menu bar is considered the prime reference point for the user to locate commands. The Cinnamon desktop for example, explicitly chooses to retain traditional user interfaces (titlebars, menubars). It therefore forked Nautilus into Nemo, which maintains the global menu. In addition, they have created "x-apps", which are forks of the gnome apps that retain the classical title bar and the menu bar (Xedit, Xviewer, Xreader, etc.)

Solution 2:

Actually, the idea of removing the menu bar does not seem to be too bad for me because it does make the window appear neater. However, the developer had been careless in doing so because they omitted some important items in the menu, that is "preferences" and "keyboard shortcuts".

With no menu, you can no longer configure keyboard shortcuts and select behaviour when double-clicking an executable text file. Wait, that is not right because if you maximize the nautilus file manager window, the "Files" menu is back, and you can open the "preferences" and "keyboard shortcuts" dialog. This design is very bad because it is not systematic and it breaks the consistency of the application, in the way that the "preferences" and "keyboard shortcuts" dialog is not accessible unless you maximize the window. At least it does not make sense to me.