To upgrade your site, the following changes are required:
Zen Cart v1.3.8:
Edit your /includes/modules/payment/paypalwpp.php file and make the following changes at lines 1040-1041.
Edit your /includes/modules/payment/paypaldp.php file and make the following changes at lines 886-887.
Basically just changing the 2 references of "verisign.com/transaction" to "paypal.com":
Code:
$doPayPal->_endpoints = array('live' => 'https://payflowpro.verisign.com/transaction',
'sandbox' => 'https://pilot-payflowpro.verisign.com/transaction');
becomes
Code:
$doPayPal->_endpoints = array('live' => 'https://payflowpro.paypal.com',
'sandbox' => 'https://pilot-payflowpro.paypal.com');