How to reset monitor/screen/display setup in KDE on openSuSE 42.1

May 2016

Problem description:

Corrupted KDE Display/Monitor setup resulting in blank external screen/monitor after login to KDE/plasma.

Background Information:

In my case the problem was caused by docking suspended laptop to external screen/monitor and waking it up.
I was able to normally login to a text terminal using Ctrl + Alt + F1 (or F2/F3/F4/...).
Logging to laptop screen or Gnome with the external worked normally too.

openSuSE version: 42.1
KDE version: 4.14.18

Solution used:

Remove offending screen configuration file in directory: .local/share/kscreen
The screen configuration files are named by the screen ID and the files is human readable.
If unsure which screen setup file is the problematic one, you can remove them all by:

rm .local/share/kscreen/*