Error when creating a Sales Order using the graph object - acumatica

Question

I'm trying to create a Sales Order from the PO screen using the SOOrderEntry graph object. I'm selecting the branch using a technique from another Stack Overflow case, and I continuously get the following error:
I can't figure out why this error is coming up, since I'm setting the CustomerID. Here's the code:
public class POOrderEntryExt : PXGraphExtension<POOrderEntry>
{
public override void Initialize()
{
Base.action.AddMenuAction(CreateSO);
}
public PXAction<POOrder> CreateSO;
[PXUIField(DisplayName = "Create Sales Order", MapEnableRights = PXCacheRights.Select, MapViewRights = PXCacheRights.Select)]
[PXButton]
protected virtual void createSO()
{
SOOrderEntry sograph = null;
SOOrder soorder = null;
SOLine soline = null;
//Let's get the current data from the screen we're in...
var poorder = (POOrder)Base.Document.Current;
PXResultset<POLine> res = PXSelect<POLine, Where<POLine.orderNbr, Equal<Required<POLine.orderNbr>>>>.Select(Base, poorder.OrderNbr);
using (PXLoginScope ls = new PXLoginScope("admin"))
{
//Create a new instance of the AP Bills screen graph..
sograph = PXGraph.CreateInstance<SOOrderEntry>();
//Get the branch...
var branch = (Branch)PXSelect<Branch, Where<Branch.branchCD, Equal<Required<Branch.branchCD>>>>.Select(Base, "WI-NVC VET");
//soorder.BranchID = branch.BranchID;
//This handler is added per RD from another Stack Overflow case. It's necessary to select the Branch...
sograph.FieldDefaulting.AddHandler<SOOrder.branchID>((s, e) =>
{
e.NewValue = branch.BranchID;
e.Cancel = true;
});
soorder = new SOOrder();
//The OrderType...
soorder.OrderType = SOOrderTypeConstants.SalesOrder;
sograph.Document.Insert(soorder);
soorder.OrderDate = (DateTime?)DateTime.Now;
soorder.RequestDate = (DateTime?)DateTime.Now;
//Get the customer id...
var bacct = (BAccountR)PXSelect<BAccountR, Where<BAccountR.acctCD, Equal<Required<BAccountR.acctCD>>>>.Select(Base, "NE-C003118");
soorder.CustomerID = bacct.BAccountID; // (int?)5454;
sograph.Document.Update(soorder);
sograph.Actions.PressSave();

Answer 1

This is very import to always assign the result of PXCache Insert or Update method invocation to some local variable so further you make changes to the object from the cache, rather than to a legacy record, which has nothing in common with PXCache.
The issue should be resolved by the following tiny change:
soorder = new SOOrder();
soorder.OrderType = SOOrderTypeConstants.SalesOrder;
soorder = sograph.Document.Insert(soorder);