KDE help: 'KDE lost my widget!'

Recently I was arranging widgets on my dual screens when I tried to drag one from one monitor to the other. I dropped it where I wanted it to go, and was surprised to see it wasn't there.

No matter, I thought. I opened the widget panel to add it again and was confused to see that there was already a green check mark on the widget, indicating that as far as KDE was concerned, I was already using it.

I looked again but it was no-where to be seen.

A bit of searching around led to an answer.
  • Minimize the running applications so you have a clear view of the desktop where the widget should be. 
  • Right click on the desktop. Select  Desktop Settings.
  • Under the View > Layout, select "Newspaper Layout".  You should see the missing widget(s)  at the center of the desktop. (I achieved success using some of the other alternate layouts as well).
Another thread I consulted recommended rotating the display of the screen where the widget went AWOL.  Do not do this with KDE's own Display settings as it will make both screens unreadable. However,  if the monitor's own physical controls have the ability to rotate the display, try at your own peril.