Magento Theme Checkout Configuration

Paymant Page Redirection Issue ## Deliverables We currently moved to Paypal Website Payments Pro but after all the details were inserted into magento, we had a small problem during the checkout. The transaction is successfull but the page does not get redirected to a successfull page. Paypal has sent a screenshot of where the error occurs and why it is occuring, "there seems to be an issue with the template files for your site. The following error showed up on the last step of the checkout. The error shows up on the /checkout/onepage/saveOrder." I would like a solution provided to me so I can implement the same solution to other of my sites. They said this would be a small configuration for the programmer.