WorldPay Module for ZenCartv1.3x

[kelvyn]

PHP Version: 5.2.0 (Zend: 2.2.0)

OK, that was my problem, now running PHP Version 4.4.4.

I've tried the fix mention a few up by changing
if(isset($HTTP_POST_VARS['transId'])) {$transId = $HTTP_POST_VARS[transId];}
to
if(isset($_POST['transId'])) {$transId = $_POST[transId];}

but again, no luck. I just get the

Sorry, there was an error in processing this transaction:
The information sent from the merchant's site is invalid or incomplete. Please send the following information to the merchant:

The transaction cannot be processed due to one or more of the following:

    * the installation ID field is blank or contains invalid characters
    * a different submission protocol is required. For instance, a more secure submission may be required
    * the installation number is invalid

screen again.

We have completely changed the URL and server we operate from (which is listed in the config) but Worldpay say this doesn't matter, as long as Callback is working.