Making a copy of Scrivener

I used FireWire and Target Disk Mode to transfer a copy of Scrivener from my iMac to my MacBook. When I started up Scrivener on the MacBook, it asked for my user name and serial number which I keyed in. But an alert message says the info is wrong. The serial number and user name are correct. What am I doing wrong?

Hopefully this page will help:

All the best,