MouseGoddess, maybe the 'drop dead date' of Deskscapes trial download expired.
I'd send an email to support@stardock.com and don't write again until you hear from a person describing the problem and include this url.
Even if the trial stopped working, it shouldn't have affected Fences.
If you still have Impulse, try checking "Verify Installation" by Shift+Right click on Deskscapes, and after closing and reopening Impulse, doing the same for Fences.
When you downloaded Deskscapes were your antiviral and firewall turned off?