Cannot shutdown unless I use tty-Collection of common programming errors
Open a Terminal and run the following command :
unity - - reset
dconf reset -f /org/compiz/
Log out of your desktop session and back into Unity for changes to take effect.
Step 2
To refresh your Unity launcher with the default set of icons, run the following in a Terminal:
unity --reset-icons
This command will “restart” Unity immediately, running from the Terminal. Closing the Terminal will also ‘close’ Unity, so it’s best to log out and back in after running this command.
Hope this might work indirectly.