If any product in the CDON Order is out of stock in Magento 2 store. If any product in the CDON order is disabled in the Magento 2 store. If any product does not exist in Magento 2 store or is deleted from the Magento 2 store after uploading on CDON. If the selected payment method in the CDON System Configuration setting is not available in Magento 2 store.