После добавления нового цифрового товара при попытке оформления первого заказа выходит следующая ошибка:
Warning: A non-numeric value encountered in /var/.../wp-content/wp-recall/add-on/users-market/index.php on line 554
Warning: Cannot modify header information - headers already sent by (output started at /var/.../wp-content/wp-recall/add-on/users-market/index.php:554) in /var/.../wp-content/plugins/wp-recall/add-on/commerce/classes/class-rcl-cart.php on line 188
Warning: Cannot modify header information - headers already sent by (output started at /var/.../wp-content/wp-recall/add-on/users-market/index.php:554) in /var/.../wp-includes/pluggable.php on line 1296
Warning: Cannot modify header information - headers already sent by (output started at /var/.../wp-content/wp-recall/add-on/users-market/index.php:554) in /var/.../wp-includes/pluggable.php on line 1299
После перезагрузки страницы выходит сообщение о том, что заказ сформирован. В чём может быть причина?