Follow
apt-get install gnome-session-fallback
Install and start GDM (I choose GDM instead of lightgdm when it gave me the choice)
apt-get install gdm
if you already installed GDM ,gnome before use
dpkg-reconfigure gdm
Follow
http://www.howtoforge.com/how-to-install-vnc-server-on-ubuntu-14.04
Then edit
~/.vnc/xstartup
with the following:
#!/bin/sh
def
export XKL_XMODMAP_DISABLE=1
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
gnome–panel&
gnome–settings–daemon&
metacity&
nautilus&
gnome–terminal&
Then
Reboot