I've been getting this dialog on the Desktop at least once every day for the past few days. It shows up in the bottom right corner of the screen.
I don't Hibernate, Sleep, or Shut down my computer, so it has nothing to do with restart from any of these states.

If I check at "C:\ProgramData\Stardock\DeskScapes," the License.sig file is there. I just close this dialog, and DeskScapes works fine without asking to activate.