After updating Z17, or maybe I changed something? When I could no longer start the "Settings" dialogue, or its sub dialogs such as Display Settings etc. links on desktop with right-click.
Well I searched web using terminology from the desktop right-click menu, but nothing turned up.
I SOLVED this when I looked in the Software Centre and found out from there that so called "Settings" is actually called 'Gnome Settings' and that was (from Software Centre) no longer installed - Click the (SC) Install button and all is fixed.
However when this app is installed in SC it doesn't show up when from CLI console with which gnome-settings