Running KDE 16.04 dual boot with Windows 10. I'm new to Linux and KDE so please bear with me. I'll go through the whole adventure of how I got to the black desktop. This process was spread out over 2-3 days so all the stuff I tried is shown but not necessarily in chronological order which seems irrelevant for this adventure. A useful adventure because I;m learning about sudo com

Even though the desktop was blank everything else worked. Login; see the splash screen with the K+ Gear icon; see progress bar. All the the information in the panel along the bottom of the screen (time; wireless connected and so on) is correct. All the launchers in that panel work. THe application launcher works. Just a black desktop.

Installed Inkscape (Used Synaptic) because I needed to mke some drawings. Tool tips do not show in Plasma 5 ( known issue some discussion in forums). Checked the forums. Inkscape tool tips show in fvwm and Crystal-fvwm. Installed these desktops using Synaptic. The tool tips are viewable. Inkscape did not have some features I needed so I uninstalled.

apt-get remove inkscape.

Did not like Crystal desk top. Uninstalled.
apt-get remove fvwm
apt-get remove crystal-fvwm

Stuff gets removed.
sudo reboot and desktop.

The next day, all should be good. Black desktop on login.

Checked the forums. Google sudo remove. Learned about the difference betwwen sudo remove and sudo purge.
apt-get purge fvwm received prompt message to use autoremove
apt-get purge crystal-fvwm
apt-get autoremove fvwm; files removed
apt-get autoremove crystal-fvwm not found
apt-get autoremove inkscape not found
apt-get reboot to black desktop.
Checked the forums. Found the following link:

viewtopic.php?f=289&t=125034&hilit=desktop+black
Cut and pate the first sudo command

apt-get mv ~/.config/kwinrc ~/.config/kwinrc-old && kwin_x11 --replace

Progress at last; a screen full of errors is progress.

Gave the following output:

john@john-X555LAB:~$ sudo mv ~/.config/kwinrc ~/.config/kwinrc-old && kwin_x11 --replace
[sudo] password for john:
QXcbConnection: XCB error: 8 (BadMatch), sequence: 1361, resource id: 29360133, major code: 42 (SetInputFocus), minor code: 0
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 5500 (Broadwell GT2)
OpenGL version string: 3.0 Mesa 11.2.0
OpenGL shading language version string: 1.30
Driver: Intel
GPU class: Unknown
OpenGL version: 3.0
GLSL version: 1.30
Mesa version: 11.2
X server version: 1.18.3
Linux kernel version: 4.4
Requires strict binding: yes
GLSL shaders: yes
Texture NPOT support: yes
Virtual Machine: no
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1529, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1530, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1531, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1532, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1533, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1534, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1539, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1540, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1541, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1542, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1543, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1544, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1545, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1546, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QMetaProperty::read: Unable to handle unregistered datatype 'KWayland::Server::SurfaceInterface*' for property 'KWin::Toplevel::surface'
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28431, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28432, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28433, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28434, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28442, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28452, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28461, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 28471, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 32402, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 32412, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 32422, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 32431, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 32432, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 32445, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 57561, resource id: 0, major code: 14 (GetGeometry), minor code: 0

Time to bail out and get help.
Whatever Qxcb is; stuff is funky.
Help greatly appreciated.


John