CPT issue: Warning: call_user_func_array() expects parameter 1 to be a valid callback

I'm getting an error on the admin screen for the custom post type. I've searched lots of other answers but see nothing in my code that could be causing it. Here's my code. Any help would be greatly appreciated.

// Register the post types and taxonomys
add_action('init', 'register_post_types');
function register_post_types(){ 
// Property Post Type
$labels = array(
    'name'               = __('Properties'),
    'singular_name'      = __('Property'),
    'add_new'            = __('Add New'),
    'add_new_item'       = __('Add New Property'),
    'edit_item'          = __('Edit Property'),
    'new_item'           = __('New Property'),
    'view_item'          = __('View Property'),
    'search_items'       = __('Search Properties'),
    'not_found'          = __('Nothing found'),
    'not_found_in_trash' = __('Nothing found in Trash'),
    'parent_item_colon'  = '',
);

$args = array(
    'labels'               = $labels,
    'public'               = true,
    'publicly_queryable'   = true,
    'show_ui'              = true,
    'register_meta_box_cb' = 'custom_meta_boxes',
    'query_var'            = true,
    'menu_icon'            = null,
    'rewrite'              = true,
    'capability_type'      = 'post',
    'hierarchical'         = false,
    'menu_position'        = 5,
    'supports' = array( 'title', 'editor', 'genesis-seo', 'thumbnail','genesis-cpt-archives-settings' ),
    'has_archive' = true,
); 

register_post_type('property' , $args);

// Property Taxonomy
$taxononmy_args = array(
    'hierarchical'   = true, 
    'label'          = "Categories", 
    'singular_label' = "Category", 
    'rewrite'        = true,
    'show_admin_column' = TRUE
);

register_taxonomy("property_categories", array("property"), $taxononmy_args);
}