Ubuntu 14.04 Nautilus has no menu - File, Edit etc. don't exist

Run dconf-editor, navigate to org > gtk > settings > file-chooser, then untick show-hidden.

Press Ctrl+h to show hidden files, press it again again to hide them.

I think what you're asking about might be "a feature, not a bug".

Take a look at: http://arstechnica.com/information-technology/2014/02/ubuntu-desktop-moving-application-menus-back-into-application-windows/

It says:

... in May 2012. "By design, the global menu bar displays the menu of the focused window. This proves awkward in some applications with dialogs and multiple windows."

The intent of moving application-specific menus into the global menu bar was to leave more room for content in applications.

Fortunately:

Ubuntu developers wanted to "propose a solution to fix the main UX bug we have [had] in Unity since its very first release: the menus being hard to find or too far from their parent window,"

To find this solution:

Hover over an empty space in the background. Click the menu-button on your mouse (usually the right button). A menu appears; select "Change Desktop Background".

A window will open up, with "All Settings" | "Appearance" and two tabs: "Look" and "Behavior". "Look" will be selected; select "Behavior".

Under "Show the menus for a window", select the "In the window's title bar" option.

That should do it.

This issue can be fixed by installing nemo:

First remove nautilus with

sudo apt-get remove --purge nautilus

then download nemo

sudo add-apt-repository ppa:webupd8team/nemo
sudo apt-get update
sudo apt-get install nemo nemo-fileroller

Then your folders might disappear in places like the desktop. They should return after some time. If not, then please restart the PC.

You don't have to delete nautilus, but then you have to keep opening nemo and do all from there. Also, if you search for nemo it will show you a application called Files. Don't get confused by that, it's still nemo.