i have been looking for answers to this for days i found this answer on kde suport .
waldelf Wrote:
have you tried deleting your
~/.kde/share/config/plasma-appletsrc
~/.kde/share/config/plasmarc
i could not find plasmarc anywhere . I however searched the drive and found plasma-appletsrc
i f ound it here and
/usr/share/kubuntu-default-settings/kde4-profile/default/share/config$/plasma-appletsrc I opened terminal and ran this
sudo rm /usr/share/kubuntu-default-settings/kde4-profile/default/share/config$/plasma-appletsrc
and my systems is back!!!!!
sudo rm /usr/share/kubuntu-default-settings/kde4-profile/default/share/config/plasma-appletsrc worked for me.. thanks a ton! Running it now on my mac in virtualbox... very nice