$_child->parent = null;
$_child->errors = new WP_Error( 'theme_parent_invalid', sprintf( __( 'The "%s" theme is not a valid parent theme.' ), $_child->template ) );
$_child->cache_add( 'theme', array( 'headers' => $_child->headers, 'errors' => $_child->errors, 'stylesheet' => $_child->stylesheet, 'template' => $_child->template ) );
$_child->parent = null;
$_child->errors = new WP_Error( 'theme_parent_invalid', sprintf( __( 'The "%s" theme is not a valid parent theme.' ), $_child->template ) );
$_child->cache_add( 'theme', array( 'headers' => $_child->headers, 'errors' => $_child->errors, 'stylesheet' => $_child->stylesheet, 'template' => $_child->template ) );