getObject returning array not Object for runProcessor('security/user/create' ret

<?php
        $parentRes = $this->modx->runProcessor('security/user/create', array(
                    'username' => $_POST['firstname'] . $_POST['surname'],
                    'fullname' => $_POST['firstname'] . ' ' . $_POST['surname'],
                    'address' => $_POST['address1'],
                    'city' => $_POST['address2'],
                    'state' => $_POST['address3'],
                    'zip' => $_POST['postcode'],
                    'phone' => $_POST['phonenum'],
                    'mobilephone' => $_POST['mobilenum'],
                    'email' => $_POST['email'],
                    'newpassword' => TRUE,
                    'passwordnotifymethod' => 'e',
                    'passwordgenmethod' => 'g',
                    'class_key' => 'ParentExtUser',
                ));
        /*  Above creates user np */

        if ($parentRes->isError()) {
            if ($parentRes->hasFieldErrors()) {
                $fieldErrors = $parentRes->getAllErrors();
                $errorMessage = implode("\n", $fieldErrors);
            } else {
                $errorMessage = 'An error occurred: ' . $parentRes->getMessage();
            }
            return ($errorMessage);
        }

        $this->Parent = $parentRes->getObject(); /*This line seems to return an array not an object */

        $this->extendedParent = $this->modx->newObject('parentExtras');
        $this->extendedParent->set('priority',$_POST['priority']);
        $this->extendedParent->set('title',$_POST['title']);
        /* Above creates a new object based on extended schema np and sets it's variables */

        $this->Parent->addOne($extendedParent); /* Returns the error [b]Call to a member function addOne() on a non-object[/b] */
        $this->Parent->save();
?>