You must have a news item on the homepage of the site if you want to use the 'Latest Forum posts' menu that is showing above this menu.

The latest forum posts menu in the menu manager is a totally separate plugin, and does not have to be enabled in the menu manager.

The 'Latest Forum Posts' menu shown above is controlled through the Plugin manager on the frontpage of the admin section, click the blue paper clip to view/change the menu settings.