When we perform Create/Update/Upsert operation in a NetSuite object such as Invoice/SalesOrder, which has sublist fields like AddressList/ItemList/InventoryList, we may encounter an error like - "Adding new line to sublist item is not allowed". This error occurs when we send values to a few fields/elements of the sublist instead of sending values to all the fields/elements of that sublist.
Add value of "FALSE" in "@replaceAll" attribute of the field AddressList/ItemList/InventoryList, as per below screenshot.