Microsoft.Xrm.Sdk.SaveChangesException generated in Dynamics CRM plug-in

Question

The following code is created in a Microsoft Dynamics CRM plug-In. The code executes after a product Entity is updated. There is a custom field in the product Entity called labourRate. All the fields are selected to be passed to the plug-in:

    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();
        }
    }

The above code results in the following error:

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>

Answer 1

Are you On Premise or Online? If you are On Premise attach to the CRM process on the Microsoft Dynamics CRM server and debug your code to pinpoint which line is throwing the exception.

If your are online, i'm afraid your stuck with line by line tracing.

More info here http://msdn.microsoft.com/en-us/library/gg328574.aspx