RestartPlasma

To restart the Plasma shell: (from this askubuntu answer by Korcia):

In KDE 4, you can do:

killall plasma-desktop #to stop it
kstart plasma-desktop #to restart it

In KDE 5 use:

killall plasmashell #to stop it
kstart plasmashell #to restart it

In KDE > 5.10 use:

kquitapp5 plasmashell
kstart5 plasmashell

Sometimes plasmashell is not responding so kquitapp5 fails after a timeout and you have to get back to killall. So in a nutshell, I would do :

# For KDE 4
killall plasma-desktop && kstart plasma-desktop

# For KDE 5 < 5.10
killall plasmashell && kstart plasma-desktop

# For KDE > 5.10
kquitapp5 plasmashell || killall plasmashell && kstart5 plasmashell

If you are not sure which KDE version your run, kinfocenter --version will tell you.

You can skip the kquitapp5 plasmashell || part if you don't want to be stuck in the timeout when plasmashell is not responding.