Problem

While working with KDE my taskpannel disappeared suddenly. Is there a way to restart it without logout/login and closing all my 103 Browser Tabs and 52 Terminals?

Solution

Open a local terminal and try to quit and restart the plasma-desktop

kbuildsycoca4 && kquitapp plasma-desktop && kstart plasma-desktop

If the above command does not work, because it tells you that plasma-desktop was not found or is not running, then try with the following command

kstart plasma-desktop

Reference: http://www.humbug.in/2010/killquit-and-restart-plasma-on-kde/