I can't access custom taxonomy page listing

Question

I had an issue with a custom taxonomy and a custom post type using the same URL.

My URL I am using for my post type is /news and then I have a taxonomy which I need to have /news/cars

I followed this post to get my URL's to work but now I cant access the actual taxonomy listing pages as i get a 404.

Mixing custom post type and taxonomy rewrite structures?

This is my code I am using to do this functionality:

    function register_custom_post_types() {
    $args = array(
        'labels' => array(
            'name' => __( 'News' ),
            'singular_name' => __( 'News' )
        ),
        'menu_position' => 5,
        'public' => true,
    'query_var' => 'news',
        'has_archive' => 'news',
        'hierarchical' => true,
        'taxonomies' => array('news_categories'),
    'publicly_queryable' => true,
        'capability_type' => 'post',
        'rewrite' => array('with_front' => false, 'slug' => 'news/%news_categories%'),
        'supports' => array('title', 'editor', 'thumbnail', 'revisions', 'page-attributes')
    );
    register_post_type( 'news', $args);

}
add_action( 'init', 'register_custom_post_types' );

add_action( 'init', 'create_my_taxonomies', 0 );

    function create_my_taxonomies() {
        register_taxonomy(
            'news_categories',
            'news',
            array(
                'labels' => array(
                    'name' => 'News Categories',
                    'add_new_item' => 'Add New Category',
                    'new_item_name' => "New Category"
                ),
                'query_var' => 'news',
                'show_ui' => true,
                'show_tagcloud' => false,
                'hierarchical' => true,
                'rewrite' => array(
                    'with_front' => false,
                    'slug' => 'news'
                )
            )
        );
    }

    add_filter('post_type_link', 'news_term_permalink', 10, 4);
    function news_term_permalink($post_link, $post, $leavename, $sample) {
        if ( false !== strpos( $post_link, '%news_categories%' ) ) {
            $glossary_letter = get_the_terms( $post->ID, 'news_categories' );
            $post_link = str_replace( '%news_categories%', array_pop( $glossary_letter )->slug, $post_link );
        }
        return $post_link;
    }

Answer 1

The only problem that I have found is 'query_var' => 'news' in register_taxonomy(). Change it to 'query_var' => true and it will start working.

function create_my_taxonomies() {
        register_taxonomy(
            'news_categories',
            'news',
            array(
                'labels' => array(
                    'name' => 'News Categories',
                    'add_new_item' => 'Add New Category',
                    'new_item_name' => "New Category"
                ),
                'query_var' => true,
                'show_ui' => true,
                'show_tagcloud' => false,
                'hierarchical' => true,
                'rewrite' => array(
                    'slug' => 'news'
                )
            )
        );
    }

Reference: Codex Register Taxonomy