I have followed Cody Fauser's tutorial 'PayPal Express Payments with
and its working fine for me in my local system. But when I try to move
the code in my server, the code is not working.I get the following
"This transaction is invalid. Please return to the recipient's website
to complete your transaction using their regular checkout flow. "
NB: I was logged into the developer.paypal.com when trying to do the
checkout. Can anyone throw some light into this ?