WooCommerce Product Bundles - PHP Notice: Function product_type was called incorrectly...

Overview of the issue

If you are using WooCommerce Product Bundles plugin, you will notice that a PHP notice occurs when a bundle product is added to the cart:

PHP Notice: Function product_type was called incorrectly. Product properties should not be accessed directly...

Workaround

Please, make sure of having a full site backup of your site before proceeding.

• Open …/wp-content/woocommerce-multilingual/compatibility/WcProductBundles/class-wcml-product-bundles.php file
• Look for line 796.
• Replace:

  if ( isset( $cart_item['bundled_items'] ) && $cart_item['data']->product_type === 'bundle' ) {
  

• With:

  if ( isset( $cart_item['bundled_items'] ) && $cart_item['data']->get_type() === 'bundle' ) {