Woocommerce：在class-wc-product-variable.php文件中为foreach（）提供的参数无效

Question

I'm creating a type of variable product customized for my theme, I've managed to appear in the dropdown of product data and that can be saved without causing conflict. The problem is that seeing the product in frontend gives me the following error:

Warning: Invalid argument supplied for foreach() in /Applications/MAMP/htdocs/canopy/wp-content/plugins/Woocommerce/includes/class-wc-product-variable.php on line 83

I have traced the problem to the file Wordpress/includes/data-stores/class-wc-product-variable-data-store-cpt.php but the truth is that I do not know what else to do.

I leave the code that I wrote for this:

WC_Product_variable_canopytour.php

class WC_Product_Variable_CanopyTour extends WC_Product_Variable {
    public function __construct( $product ) {
        $this->product_type = 'variable_canopytour';
        parent::__construct( $product );
    }

    public function get_type() {
        return 'variable_canopytour';
    }
}

class-woocommerce-custom-product.php

class WCB_Woocommerce_CanopyTour_Product_Type {
    private $wcb;
    private $version;

    public function __construct( $wcb, $version ) {
        $this->wcb = $wcb;
        $this->version = $version;
    }

    public function register_canopytour_product_type() {
        remove_action( 'woocommerce_single_product_summary', 'woocommerce_template_single_price', 10 );

        include_once(get_template_directory() . 'woocommerce/WC_Product_variable_canopytour.php');
    }

    public function add_canopytour_product( $types ) {
        $types[ 'variable_canopytour' ] = __( 'Variable Canopy Tour', $this->wcb );
        return $types;
    }

    public function get_tour_product_class($classname, $product_type) {
        if ( $product_type === "variable_canopytour" ) {
            $classname = 'WC_Product_Variable_CanopyTour';
        }
        return $classname;
    }

    public function wcb_admin_footer() {
        if ( 'product' != get_post_type() ) :
            return;
        endif;

        ?><script type='text/javascript'>
            jQuery( document ).ready( function() {
                jQuery( '.options_group.pricing' ).addClass( 'show_if_variable_canopytour show_if_simple show_if_external' ).show();
                jQuery( 'li.general_options.general_tab' ).addClass( 'show_if_variable_canopytour show_if_simple show_if_external' ).show();
                jQuery( '.variations_options.variations_tab' ).addClass( 'show_if_variable_canopytour' ).show();
                jQuery( '.enable_variation' ).addClass( 'show_if_variable_canopytour' ).show();
            });
        </script><?php
    }

    function hide_wcb_data_panel( $tabs) {
        // Other default values for 'attribute' are; general, inventory, shipping, linked_product, variations, advanced
        $tabs['shipping']['class'][] = 'hide_if_variable_canopytour';
        return $tabs;
    }
}

functions.php

include_once get_template_directory() . 'includes/woocommerce/class-woocommerce-custom-product.php';
$woo_ct = new WCB_Woocommerce_CanopyTour_Product_Type( "wcb", "1.0" );

add_action( 'init', array($woo_ct, 'register_canopytour_product_type') );
add_filter( 'product_type_selector', array($woo_ct, 'add_canopytour_product') );
add_filter( 'woocommerce_product_class', array($woo_ct, 'get_tour_product_class'), 10, 2 ); 
add_action( 'admin_head', array($woo_ct, 'wcb_admin_head') );
add_filter( 'woocommerce_product_data_tabs', array($woo_ct, 'hide_wcb_data_panel') );

I hope someone can help me understand what happens :(

Thank you!