Title: Fatal error: Call to undefined function rt_nav()
Last modified: August 22, 2016

---

# Fatal error: Call to undefined function rt_nav()

 *  [naysilva](https://wordpress.org/support/users/naysilva/)
 * (@naysilva)
 * [11 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-call-to-undefined-function-rt_nav/)
 * I’ve just edited a RT THEME’s functions.php file and changed the following:-
 * add_theme_support( ‘post-thumbnails’, array( ‘post’,’slider’,’home_page’) );
 * (well at least I think it was this) to
 * add_theme_support( ‘post-thumbnails’ );
 * as the guy had an issue with the ‘Featured Image’ now showing. Although this 
   fixed this issue I now have another problem.
 * When I load the homepage I get the following error:-
 * Fatal error: Call to undefined function rt_nav() in /home/content/70/10814870/
   html/wp-content/themes/smoke/header.php on line 198
 * Which points to this line:-
 *  <!– navigation bar –>
    <?php rt_nav($link_page,$link_cat); ?>
 * The problem is that I can’t remember what the add_theme_support options were 
   set to before.
 * I can access wp-admin and noticed that Appearance –> Menu’s isn’t showing up 
   anymore, so I believe it must have something to do with add_theme_support option.
 * Can anyone help please?

The topic ‘Fatal error: Call to undefined function rt_nav()’ is closed to new replies.

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 0 replies
 * 1 participant
 * Last reply from: [naysilva](https://wordpress.org/support/users/naysilva/)
 * Last activity: [11 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-call-to-undefined-function-rt_nav/)
 * Status: not resolved

## Topics

### Topics with no replies

### Non-support topics

### Resolved topics

### Unresolved topics

### All topics