Pandajack
Regarding my problem, it is happening again. At the moment it is occurring when I return to the computer with black screens and log back in to windows.
I have Fences back up and running and have not seen the problem occur again yet. Thanks for your help.
Tried again. I see now that the text editor window that appeared maybe because I have .VBS files associated with a text editor. Rather than the intended message box, I got this: This time, when I closed the TextPad window, it did launch the uninstaller and ran.  
OK, when I ran the purge app, all my desktops went black. My start menu disappeared. The text document that popped up told me to click ok but there was no OK. I had to cycle through my running apps with alt tab. No app with OK button. I had to close all my apps manually, then use ctrl alt delete to get to log in screen. I'm left handed but my mouse buttons were now switched, but I was able to shut down. Restarted the computer, seems OK. Fences
Windows 10 Version 20H2 OS Build 19042.928 Fences version 3.0.9.11
This is happening all the time now. Those icons are from the fences directly underneath my active window.
It does seem to be working as expected now. It's like there was some very long delay in refreshing, but now it's instant. I had just download and installed Fences for the first time today - so Fences 3.0.9.11 FYI (but I think my problem has resolved itself) Window 10 Pro No anti virus or malware software running. No desktop manager program running. Desktop is stored on OneDrive.
I came back some time later and the changes I made to the desktop folder now seem to be reflected on my actual desktop. Can't say how long this took but it was more than 10 minutes. Is this normal? How can I avoid this delay or tell Fences to refresh?
It seems that I can no longer manage my desktop contents by using the Desktop folder. Things deleted from the desktop folder do not disappear from the desktop (but no longer work). If I then try to delete the item from the desktop itself (Fences), I can't because it says it does not exist. Items that were put into fences automatically when I installed Fences (I said yes to allow this) are no longer in my actual desktop folder. If I right click on the item in Fences a