By Default the root login is not permit in KDE Plasma Desktop. To activate its root login you have to change setting of kde. the file located in directory
/etc/
kde4/kdm/kdmrcI’m using kde4 .Check yours.
Step To Activate Root Login In KDE Plasma Desktop:
- Open Terminal
- Enter The Following Command
sudo gedit /etc/kde4/kdm/kdmrc
- Now kdmrc is open.Find(ctrl+f) the string AllowRootLogin .
By default its value is false Change it to true
- Now Root Login Allowed.
- Restart and enjoy permotion.