In version 2.1.1 there is a minor bug in menu selection page (Store Front), I have more than 150 menus in my website (www.crystaldew.in) but only first four categories worked on click.
After spending hours in it and even upgrading it to latest version I found that due to menu page limit, it is not showing menu on clicking on its category, so I commented line 39-41, i.e.
if ($this->config->item('menus_page_limit')) {
$filter['limit'] = $this->config->item('menus_page_limit');
}
in /main/controllers/menus.php
It worked for me... Hopefully it will help our tastygniter community :)