Hi Rusty,

Currently, We control Merchello Customer by manual. When member login with his account, I will create new Merchello Customer by manual. I create customer at SalePreparationOperationsController: SaveAddresses() method

if (!string.IsNullOrEmpty(model.BillingName)) {

               int bupaId = 0;
                if(int.TryParse(model.BillingName, out bupaId))
                {
                    var bupa = Services.MemberService.GetById(bupaId);
                    var existedCustomer = MerchelloServices.CustomerService.GetByLoginName(bupa.Username);
                    if (existedCustomer == null)
                    {
                        var customer = new Customer(bupa.Username)
                                       {
                                           FirstName = bupa.Username,
                                           LastName = bupa.Name,
                                           Email = bupa.Email,
                                           TaxExempt = false
                                       };

                        MerchelloServices.CustomerService.Save(customer);
                        Session["CustomerKey"] = customer.Key;
                    }
                    else
                    {
                        Session["CustomerKey"] = existedCustomer.Key;
                    }
                }

            }

And I want to set customer key to Invoice when customer paid payment at SalePreparationBase

public virtual IPaymentResult AuthorizePayment(IPaymentGatewayMethod paymentGatewayMethod, ProcessorArgumentCollection args)

    {
        Mandate.ParameterNotNull(paymentGatewayMethod, "paymentGatewayMethod");

        if (!IsReadyToInvoice()) return new PaymentResult(Attempt<IPayment>.Fail(new InvalidOperationException("SalesPreparation is not ready to invoice")), null, false);

        // invoice
        var invoice = PrepareInvoice(new InvoiceBuilderChain(this));

        if (System.Web.HttpContext.Current.Session["CustomerKey"] != null)
        {
            var customerKey = Guid.Parse(System.Web.HttpContext.Current.Session["CustomerKey"].ToString());
            invoice.CustomerKey = customerKey;
        }

        MerchelloContext.Services.InvoiceService.Save(invoice);

        var result = invoice.AuthorizePayment(paymentGatewayMethod, args);

        Finalizing.RaiseEvent(new SalesPreparationEventArgs<IPaymentResult>(result), this);

        return result;
    }

But It show error delete cache key problem.

What's problem with my code?