Fatal error: Uncaught Exception: Invalid product.
in /var/www/vhosts/calendarize.it/httpdocs/wp-content/plugins/woocommerce/includes/data-stores/class-wc-product-data-store-cpt.php on line 167

Call stack:

1. WC_Product_Data_Store_CPT::read()
   wp-content/plugins/woocommerce/includes/class-wc-data-store.php:159
2. WC_Data_Store::read()
   wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-product.php:138
3. WC_Product::__construct()
   wp-content/uploads/calendarize-it/calendarize-it-payment-options-woocommerce/includes/class.rhc_pay_wc_frontend.php:255
4. rhc_pay_wc_frontend::woocommerce_add_to_cart_redirect()
   wp-includes/class-wp-hook.php:326
5. WP_Hook::apply_filters()
   wp-includes/plugin.php:205
6. apply_filters()
   wp-content/plugins/woocommerce/includes/class-wc-frontend-scripts.php:580
7. WC_Frontend_Scripts::get_script_data()
   wp-content/plugins/woocommerce/includes/class-wc-frontend-scripts.php:465
8. WC_Frontend_Scripts::localize_script()
   wp-content/plugins/woocommerce/includes/class-wc-frontend-scripts.php:634
9. WC_Frontend_Scripts::localize_printed_scripts()
   wp-includes/class-wp-hook.php:324
10. WP_Hook::apply_filters()
    wp-includes/class-wp-hook.php:348
11. WP_Hook::do_action()
    wp-includes/plugin.php:517
12. do_action()
    wp-includes/script-loader.php:2217
13. wp_print_head_scripts()
    wp-includes/class-wp-hook.php:324
14. WP_Hook::apply_filters()
    wp-includes/class-wp-hook.php:348
15. WP_Hook::do_action()
    wp-includes/plugin.php:517
16. do_action()
    wp-includes/general-template.php:3050
17. wp_head()
    wp-content/themes/twentytwelve/header.php:31
18. require_once()
    wp-includes/template.php:810
19. load_template()
    wp-includes/template.php:745
20. locate_template()
    wp-includes/general-template.php:48
21. get_header()
    wp-content/plugins/woocommerce/templates/single-product.php:22
22. include()
    wp-includes/template-loader.php:106
23. require_once()
    wp-blog-header.php:19
24. require()
    index.php:17