.net - Dynamics CRM プラグインで生成された Microsoft.Xrm.Sdk.SaveChangesException

Question

次のコードは、Microsoft Dynamics CRM プラグインで作成されます。product Entityaが更新された後にコードが実行されます。product Entity呼び出された にカスタム フィールドがありlabourRateます。すべてのフィールドが選択され、プラグインに渡されます。

    protected void ExecutePostProductUpdate(LocalPluginContext localContext)
    {
        if (localContext == null)
        {
            throw new ArgumentNullException("localContext");
        }

        IPluginExecutionContext context = localContext.PluginExecutionContext;

        //Get the IOrganizationService
        IOrganizationService service = localContext.OrganizationService;

        //create the service context
        var ServiceContext = new OrganizationServiceContext(service);
        ITracingService tracingService = localContext.TracingService;

        // The InputParameters collection contains all the data passed in the message request.
        if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity)
        {
            // Obtain the target entity from the input parmameters.
            Entity entity = (Entity)context.InputParameters["Target"];

            // get the pre entity image
            Entity preImageEntity = (context.PreEntityImages != null && context.PreEntityImages.Contains(this.preImageAlias)) ? context.PreEntityImages[this.preImageAlias] : null;

            // get the post entity image
            Entity postImageEntity = (context.PostEntityImages != null && context.PostEntityImages.Contains(this.postImageAlias)) ? context.PostEntityImages[this.postImageAlias] : null;

            Money price = new Money();

            price = (Money)postImageEntity.Attributes["price"];

            var products = from p in ServiceContext.CreateQuery("product")
                           select p;

            foreach (var product in products)
            {
                Entity e = (Entity)product;
                Money newPrice = new Money();
                decimal labourRate = 1;

                // get the preimage and postimage telephone1 value
                if (preImageEntity.Attributes.Contains("new_labourrate"))
                {
                    try
                    {
                        labourRate = (decimal)e["new_labourrate"];
                    }
                    catch
                    {

                    }
                }

                newPrice.Value = price.Value * labourRate;
                e["price"] = newPrice;
                ServiceContext.UpdateObject(e);
            }

            ServiceContext.SaveChanges();
        }
    }

上記のコードを実行すると、次のエラーが発生します。

Unhandled Exception:
System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault,
Microsoft.Xrm.Sdk, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]:  
Unexpected exception from plug-in (Execute): Plugins1.PostProductUpdate:   
Microsoft.Xrm.Sdk.SaveChangesException: An error occured while processing this request.
Detail: 
<OrganizationServiceFault xmlns:i="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://schemas.microsoft.com/xrm/2011/Contracts">
<ErrorCode>-2147220956</ErrorCode>
<ErrorDetails xmlns:d2p1="http://schemas.datacontract.org/2004/07/System.Collections.Generic" />
<Message>Unexpected exception from plug-in (Execute): Plugins1.PostProductUpdate:
Microsoft.Xrm.Sdk.SaveChangesException: An error occured while processing this request. </Message>
<Timestamp>2013-08-22T08:26:27.6655137Z</Timestamp>
<InnerFault i:nil="true" />
<TraceText>
[Plugins1: Plugins1.PostProductUpdate]
[08445d1c-5e06-e311-b80b-3c4a92dbc855: PostProductUpdate]
</TraceText>
</OrganizationServiceFault>