FulFillmentInbound.GetShipmentItems Error "Either the ShipmentId or a pair of LastUpdatedAfter and LastUpdatedBefore must be passed in input"

[adenke]

I am getting this error every single time and have verified repeatedly that I have a ShipmentId. Tried it also using a LastUpdatedBefore and LastUpdatedAfter parameter (although I need to use the ShipmentId) and get the same error every single time.

Here is part of my code if that helps:

                var shipmentItemsParameter = new FikaAmazonAPI.Parameter.FulFillmentInbound.ParameterGetShipmentItems
                {
                    
                    ShipmentId = shipmentId,
                    MarketplaceId = AmazonMarketPlaceID
                 };

                try
                {
                    // Get the shipment items
                    var shipmentItems = amazonConnection.FulFillmentInbound.GetShipmentItems(shipmentItemsParameter);

                    // Now iterate over the items (shipmentItems should be the correct collection)
                    foreach (var item in shipmentItems)
                    {
                        string sku = item.SellerSKU;
                        int quantityShipped = Convert.ToInt32(item.QuantityShipped);
                        int quantityReceived = item.QuantityReceived ?? 0;

                        // Output the shipment details for each SKU
                        MessageBox.Show($"Shipment ID: {shipment.ShipmentId}, Fulfillment Center Id:{shipment.DestinationFulfillmentCenterId} SKU: {sku}, Shipped: {quantityShipped}, Received: {quantityReceived}");
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show($"Error fetching shipment items for Shipment ID {shipmentId}: {ex.Message}");
                }