Error: Please select Order Product for selected Order, fields [tnw_shipment__Order_Item__c]
In the MagentoShop configuration, the synchronization of the ChildProduct is selected for the Configurable Products. But shipping in Magento stores only parents of the configurable products.
In these circumstances, the `Order_Item_Validation` Validation Rule must be deactivated in Salesforce.org.
Instructions
Open Salesforce Org
Go to: Setup — Create — Objects
Open "Magento Shipment Item" object
Open for Edit the "Order_Item_Validation" Validation Rule
Uncheck the "Activate" checkbox
Save the Rule
