Symptoms

• Screen is flickering in Ubuntu 16.04
• Ubuntu 16.04 displays only blank desktop screen, taskbar and desktop icons are missing
• There is only Parallels Shared Folders shortcut on Ubuntu desktop

Cause

The list of active Unity plugins is corrupted.

Resolution

1. Log in to Ubuntu GUI where you experience issues
2. Switch to text terminal by pressing Ctrl+Alt+F2 (or Ctrl+Alt+Fn+F2), log in

3. Execute the following commands:

   # export DISPLAY=:0
   
   # gnome-terminal
   

4. Switch back to Unity GUI by pressing Ctrl+Alt+F7 (or Ctrl+Alt+Fn+F7)

5. Copy-paste and execute these commands:

   # killall -9 prlcc
   
   # sudo rm /usr/lib/compiz/libprlcompiz_0_9_12_2.so
   
   # gsettings set org.compiz.core:/org/compiz/profiles/unity/plugins/core/ active-plugins "['core', 'ccp', 'composite', 'opengl', 'place', 'snap', 'imgpng', 'resize', 'commands', 'compiztoolbox', 'move', 'mousepoll', 'grid', 'wall', 'vpswitch', 'unitymtgrabhandles', 'regex', 'copytex', 'session', 'animation', 'workarounds', 'expo', 'fade', 'scale', 'ezoom', 'unityshell']"
   
   # reboot