A PHP warning is issued in Line 257 of nodehierarchy.module > nodehierarchy_form_alter

$hierarchy_form is set only if this case is met: case @$form['type']['#value'] .'_node_form':
However if that case is met, $type is never defined.

...
if ($hierarchy_form) {
$weight = function_exists('content_extra_field_weight') ? content_extra_field_weight($type, 'nodehierarchy') : 10; /* Line 257 */
$form['nodehierarchy'] = array_merge(
...