Unable create shipment from same sales order by code

Hello,

I’m trying to create shipment by code. 

I’ve already create the shipment successfully, but while I trying to create shipment from same sales order but different inventory, it’ll show message below.

Here is my code I currently use.

            foreach (SOShipmentPlan res in tmpShipmentPlan.Cache.Cached)

            {

                //foreach(list in List<SOPreShipmentLine> lists) { }

                var plan = (SOShipmentPlan)res;

                plan.Selected = true;

                SOOrder order = PXSelect<SOOrder,

             Where<SOOrder.orderType, Equal<Required<PreAddSOFilter.orderType>>,

               And<SOOrder.orderNbr, Equal<Required<PreAddSOFilter.orderNbr>>>>>.Select(this, plan.OrderType, plan.OrderNbr);

                graph.soshipmentplan.Update(plan);

                graph.CreateShipment(order, shipment.SiteID, shipment.ShipDate, false, shipment.Operation, null);

                graph.soshipmentplan.Cache.Clear();

                tmpShipmentPlan.Cache.Clear();

            }

            graph.Actions.PressSave();

Is there any way to create new shipment from same sales order by code? Thanks!