When I return to my download page I see and error containing pending_reason=address

After payment if you see an error message on return containing pending_reason=address like this this

Transaction not completed. payment_status=Pending  pending_reason=address result=VERIFIED

then this is because your customer did not include a confirmed shipping address and your Payment Receiving Preferences is set to allow you to manually accept or deny each of these payments. You must change your profile to automatically handle these payments in your Paypal account.