/*
 * Error
 *
 * [14-Jul-2015 15:22:08 UTC] PHP Fatal error:  Cannot unset string offsets in ../wp-content/themes/startuply/functions.php on line 906
 *
 * Fixed by added an isset
 */

function startuply_set_menus_columns($columns ) {
		$desc_key = 'managenav-menuscolumnshidden';
		$hidden   = get_user_option( $desc_key );
		$user_id  = wp_get_current_user()->ID;

		// default menu meta-boxes array ( 0 => 'link-target', 1 => 'description', 2 => 'xfn', 3 => 'css-classes' );
		if ( FALSE !== ( $key = array_search( 'css-classes', $hidden ) ) ) {
				if( isset( $hidden[ $key ] ) ) {
					unset( $hidden[ $key ] );
				}
				update_user_option( $user_id, $desc_key, $hidden );
		}

		return $columns;
}
add_filter( 'manage_nav-menus_columns', 'startuply_set_menus_columns', 99 );