Step 2 of 3 Fatal Error at Checkout

Hi,

We keep getting the following error message:

Step 2 of 3 - Payment Information

Shipping Method
Payment MethodReview OrderOrder Complete

Fatal error: Call to undefined function: in_special_checkout() in /home/sites/125ccbikers.co.uk/public_html/shop/includes/templates/cherry_zen/templates/tpl_checkout_payment_default.php on line 50

Having looked at the path it says this on line 50:

<?php // ** BEGIN PAYPAL EXPRESS CHECKOUT **
if (!$payment_modules->in_special_checkout()) {
// ** END PAYPAL EXPRESS CHECKOUT ** ?>

The thing is, we don't have PayPal Express, nor can we find a download for it.

Can anyone help?