Selecting folder in places does not open nautilus

Sometimes a user will mess up file associations, often the result of this is that trying to open up a folder through the places menu opens rhythm box instead.

To correct this edit .local/share/applications/mimeapps.list

For instance it might read

[Added Associations]
inode/directory=rhythmbox.desktop;
x-content/video-dvd=vlc.desktop;

it should read:

[Added Associations]
inode/directory=nautilus.desktop;
x-content/video-dvd=vlc.desktop;