Hello,
I downloaded Fences directly from the Stardock fences site, and it is different from the one provided when I purchased Fences! I don't know if I have the right file!
Then I followed the instructions: save layout, purge, reboot, install, reboot.
I was afraid I had lost the layout of the fences on my desktop, but by restoring a layout backup I was able to find my fences again.
The situation is the same : no "Unlock Fences" item displayed.