Notice: Only variable references should be returned by reference in C:\projects\vendors\Zend\Pdf\Element\Reference.php on line 207

The notice goes away when I change line 207 from this:

public function &__get($property)

public function __get($property)

This will keep the PDF from rendering in the browser due to headers already being sent.

Having your error_reporting level kept low would also keep this from appearing.