I've sent TWO support tickets to Stardock that have gone unanswered... Fences stopped working and will not accept my paid license number.... wondering if I'm the only one...
Stardock is closed on the weekend.
Having said that, it appears you are trying to activate Fences 3 with a Fences 2 serial. Try using your Object Desktop key instead.
Lastly, please note that, as stated in the support confirmation email, when you reply to a case in moves your case to the end of the queue.