Not sure of the cause of the error, but if you send you mac address, I can generate the license file to activate Design Extender for you.
On windows, To find out the MAC address:?
1) Go to the Start Menu -> Run. Type "cmd" and click on OK to bring up a command prompt.?
2) At the command prompt type "ipconfig /all > c:\\ipconfig.txt"?This will create a file in your C drive called ipconfig.txt. This file will have the MAC address in it.
1) Open System Preferances
2) Go To Network
3) in the list of connections, select the active one, and click the advanced button
4) Go to the Ethernet tab and note the Ethernet ID