Unity Launcher and Top Panel disappeared in 14.04

Solution 1:

Enter the following commands:- Ctrl+Alt+F1 login there with username and password

WARNING! THE FOLLOWING COMMAND WILL TERMINATE YOUR ACTIVE SESSION!

try:

sudo service lightdm restart

If restarting lightdm doesn't fix the problem, install aptitude and then install unity:

sudo apt-get install aptitude
sudo apt-get update && sudo aptitude -f install && sudo aptitude dist-upgrade
sudo aptitude install unity

Read the outputs carefully. If you do have broken dependencies, aptitude will give you the "solution" of NOT installing unity. Say no to this solution. Then it will give you another solution which will install broken dependencies. Say yes to this one. Once installation is complete, sudo service lightdm restart again. If you still have some issues, also reinstall ubuntu-desktop:

sudo apt-get install --reinstall ubuntu-desktop

followed by another sudo service lightdm restart.

(Credit to @DinGODzilla from this question)

Solution 2:

Hold down Alt-F2, which will bring up a dialog to enter terminal commands. There, type the command cinnamon-launcher and hit enter. That should restore the panel.

I am using Ubuntu 14.04

Solution 3:

I have same issue in ubunt 14.04, i fix it by below steps

1. ctrl+alt+f1
2. enter username and password
3. run mv ~/.config ~/.config_backup
4. run sudo service lightdm restart

Hope it will work