Hello,
Sorry to hear you are having issues. Fences 3 was first introduce back in 2017, and it has stop actual developing since Fences 4 was introduced in 2021. I wonder why you did not purchase Fences 4, if you said you purchased Fences 3, 3 years ago, since Fences 4 was actually out by then. For reference: https://www.stardock.com/products/fences/history.
However, I understand your expectation, one question, was this issue appeared when you first use Fences 3, 3 years ago? What change since it not working? Probably a lot has changed, Windows 10 updates, Windows 11 updates, Multiple time graphics driver updates over the years etc. These updates will effect how your computer work, and it will effect 3rd party software, specially one that need to work with the computer system directly, such as Fences. Fences need to keep developing to keep up with these Windows system updates. And, development need resources.
So, to make Fences 3 work on your system, you will need to revert back your Windows to version that used to work for you and stop it from updating.
Thank you.
Basj,
Stardock Community Assistant.