Magento Payment Failure at function callDoDirectPayment() - php

Question

I am having trouble debugging the payment gateway on Magento 1.6.1 using Paypal Payments Pro. It keeps failing with the message 'There was an error processing your order. Please contact us or try again later".
I have tried examining the error logs, and have posted the results below. First time using this system and more of a front end dev but I'm managing to kind of follow along with the php.
The key line where it appears to fail is
$this->_importFromResponse($this->_doDirectPaymentResponse, $response);
Could someone explain exactly what this line does? What a sensible next step in investigating this process should be? Any additional paypal / magento specific knowledge more than welcome!
I'm guessing that since the array is created then it could be a problem transferring to paypal (my api signature should be okay - the express gateway works)- how would I go about confirming or rebuking this hypothesis?
Thanks
(first 8 lines of the var/exception.log- with the referenced code snippets, and also some extra content from the var/system.log produced by the Mage::log() functions.)
exception 'Mage_Core_Exception' with message 'There was an error processing your order.
Please contact us or try again later.' in /var/www/magento/app/Mage.php:563
Stack trace:
#0 /var/www/magento/app/code/core/Mage/Paypal/Model/Api/Nvp.php(974):
Mage::throwException('There was an er...')
if (!$this->_validateResponse($methodName, $response)) {
Mage::logException(new Exception(
Mage::helper('paypal')->__("PayPal response hasn't required fields.")
));
Mage::throwException(Mage::helper('paypal')->__('There was an error processing
your order.
Please contact us or try again later.'));
}
#1 /var/www/magento/app/code/core/Mage/Paypal/Model/Api/Nvp.php(648):
Mage_Paypal_Model_Api_Nvp->call('DoDirectPayment', Array)
public function callDoDirectPayment()
{
Mage::log("hello world");
// 2013-03-20T00:04:50+00:00 DEBUG (7): hello world
$request = $this->_exportToRequest($this->_doDirectPaymentRequest);
Mage::log($request);
// 2013-03-20T00:04:50+00:00 DEBUG (7): Array
$this->_exportLineItems($request);
if ($this->getAddress()) {
$request = $this->_importAddresses($request);
}
$response = $this->call(self::DO_DIRECT_PAYMENT, $request);
Mage::log($response);
(
[PAYMENTACTION] => Authorization
[IPADDRESS] => 81.98.95.116
[RETURNFMFDETAILS] => 1
[AMT] => 0.50
[CURRENCYCODE] => GBP
[INVNUM] => 100000063
[NOTIFYURL] => http://www.store.com/paypal/ipn/
[EMAIL] => hello#email
[CREDITCAR] => xxxxxxxxxxxxxx
[EXPDATE] => xxxxxx
[CVV2] => XXX
[ISSUENUMBER] =>
)
$this->_importFromResponse($this->_doDirectPaymentResponse, $response);
Mage::log("nothing to see here")
// This returns nothing to the system.log and so I assume is the point of failure
}
#2 /var/www/magento/app/code/core/Mage/Paypal/Model/Direct.php(343):
Mage_Paypal_Model_Api_Nvp->callDoDirectPayment()
// call api and import transaction and other payment information
/**
* Place an order with authorization or capture action
*
* #param Mage_Sales_Model_Order_Payment $payment
* #param float $amount
* #return Mage_Paypal_Model_Direct
*/
protected function _placeOrder(Mage_Sales_Model_Order_Payment $payment, $amount)
{ //...........(343)
$api->callDoDirectPayment();
$this->_importResultToPayment($api, $payment);
try {
$api->callGetTransactionDetails();
} catch (Mage_Core_Exception $e) {
// if we recieve errors, but DoDirectPayment response is Success, then set
Pending status for transaction
$payment->setIsTransactionPending(true);
}
(343)
$this->_importResultToPayment($api, $payment);
return $this;
}
#3 /var/www/magento/app/code/core/Mage/Paypal/Model/Direct.php(178):
Mage_Paypal_Model_Direct->_placeOrder(Object(Mage_Sales_Model_Order_Payment), 45)
#4 /var/www/magento/app/code/core/Mage/Sales/Model/Order/Payment.php(1026):
Mage_Paypal_Model_Direct->authorize(Object(Mage_Sales_Model_Order_Payment), 45)
#5 /var/www/magento/app/code/core/Mage/Sales/Model/Order/Payment.php(311):
Mage_Sales_Model_Order_Payment->_authorize(true, 45)
#6 /var/www/magento/app/code/core/Mage/Sales/Model/Order.php(855):
Mage_Sales_Model_Order_Payment->place()
#7 /var/www/magento/app/code/core/Mage/Sales/Model/Order.php(1073):
Mage_Sales_Model_Order->_placePayment()
#8 [internal function]: Mage_Sales_Model_Order->place()

Answer 1

Do you have debugging enabled in your PayPal settings in Magento? If so, then you should see a log show up in /var/log so you can see the RAW request and response data that was sent back and forth.
This will allow you to see the actual error code and message that came back in the response which will help you figure out what exactly went wrong.