This problem happens sometimes when ubuntu starts up. You can't really boot to the interface sometimes.
Splash Screen with the 5 dots and a message saying:
waiting for network configuration
followed by:
waiting an additional 60 seconds for network configuration
I decided to go the CLI and Alt+Ctrl+F2 approach so YOU ARE FREE to do that while you are logged in to the GUI - Okay, I will write the general steps so feel free to use whatever approach you like.
Edit /etc/network/interfaces:
sudo nano /etc/network/interfaces
If you are typing this from LXTerminal while logged in to the GUI then:
gksudo leafpad /etc/network/interfaces
Remove whatever written there and just keep this:
auto lo
iface lo inet loopback
It is very good idea to keep a backup copy of "interfaces" file just in case so please make sure to save a "interfaces.bak" file before you do anything
Ctrl + O if you are using nano and Ctrl + S (File > Save) if you are using leafpad.
Ctrl + X if you are using nano and Ctrl + Q (File > Quit) if you are using leafpad.
Reboot.
Done.
