Fences 3 installed, but not usable
Functionality cannot be activated with the mouse
I've installed and successfully activated Fences on my Surface Notebook.
When I start Fences by clicking on the icon, a popup screen tells me "it seems not to be installed":

I've uninstalled and installed it several times: Nothing changes.
When I click on "OK", the program starts, and I can configure the functionality properly.

BUT:
Afterwards the desktop does not react in the supposed way.
The activation of Fences with the mouse is not an displayed option in the context menu of the popup window:

as if the program weren't installed.
In the Control panels list of installed programs, Fences is shown correctly:

What's the next step, to be able to use the functionality of fences in the appropriate way?
Kind regards,
Enno.