bump , this looks interesting
anybody have anything to say
A bit surprised that a VIP that too with Executive access is dumb enough to understand that the thread is off topic. Anyway, If you read the SQL error that is thrown you will understand easily that before the buyer is taken to this registration page, details like username, first name, last name, PayPal email, email, plan id, etc are required and it seems that these details are automatically fetched when redirected to sign up page.
You have not filled in those details and that is the reason why you are getting an error.