tom on "[Plugin: WooCommerce] PHP Fatal error: Call to a member function add_product()"

Could you please tell why these error is come and how to solve this ?

PHP Fatal error: Call to a member function add_product() on boolean in /home2/klickonc/public_html/wp-content/plugins/woocommerce/includes/class-wc-checkout.php on line 222

https://wordpress.org/plugins/woocommerce/