Uncaught Error: The script tried to modify a property on an incomplete object

Fatal error: Uncaught Error: The script tried to modify a property on an incomplete object. Please ensure that the class definition “Wpil_Model_Link” of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide an autoloader to load the class definition
in?/home/nginx/domains/ourdomain.com/public/wp-includes/formatting.php?on line?5148

Call stack:

1. map_deep()
   wp-includes/formatting.php:5143
2. map_deep()
   wp-includes/formatting.php:2855
3. stripslashes_deep()
   wp-includes/formatting.php:5804
4. wp_unslash()
   wp-includes/meta.php:55
5. add_metadata()
   wp-content/plugins/woocommerce/includes/data-stores/class-wc-data-store-wp.php:144
6. WC_Data_Store_WP::add_meta()
   wp-content/plugins/woocommerce/includes/class-wc-data-store.php:224
7. WC_Data_Store::__call()
   wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-data.php:700
8. WC_Data::save_meta_data()
   wp-content/plugins/woocommerce/includes/data-stores/class-wc-product-data-store-cpt.php:149
9. WC_Product_Data_Store_CPT::create()
   wp-content/plugins/woocommerce/includes/class-wc-data-store.php:186
10. WC_Data_Store::create()
    wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-product.php:1435
11. WC_Product::save()
    wp-content/plugins/woocommerce/includes/admin/class-wc-admin-duplicate-product.php:178
12. WC_Admin_Duplicate_Product::product_duplicate()
    wp-content/plugins/woocommerce/includes/admin/class-wc-admin-duplicate-product.php:113
13. WC_Admin_Duplicate_Product::duplicate_product_action()
    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-admin/admin.php:419
17. require_once()
    wp-admin/edit.php:10