Please enter a valid admin navigation link ID.
Please enter a valid admin navigation section ID.
Please enter a valid admin navigation tab ID.
However there are no link IDs, section IDs and tab IDs for the admin navigation in the ACP. There is only a normal admin navigation ID, whose error message is used in library/XenForo/DataWriter/AdminNavigation.php.
So what's the reason for putting those messages in xenforo when they are not used at all?