System.InvalidCastException:Microsoft Dynamics CRM遇到错误

我正尝试使用Microsoft Dynamics CRM SDK以编程方式更新记录。不幸的是，在我提取记录、更新字段并调用服务代理上的.Update()方法后，我得到了以下异常：

[System.ServiceModel.FaultException<Microsoft.Xrm.Sdk.OrganizationServiceFault>]
System.InvalidCastException: Microsoft Dynamics CRM has experienced an error. 
Reference number for administrators or support: #B08B34D9"  
System.ServiceModel.FaultException<Microsoft.Xrm.Sdk.OrganizationServiceFault>

由于我以前从未使用过CRM，而且公司内部目前使用CRM的资源非常有限，我不知道如何/从哪里开始调查异常，也不知道它可能来自哪里。

程序从以下方法开始。这只需查询数据以查找匹配的EIN编号。如果没有找到记录，那么我使用.Create()方法。如果找到记录，我们将更新Dynamics中当前存在的项目。

    public string UpdateDynamics(AgentTransmission agt)
    {
        ConditionExpression condition = new ConditionExpression();
        condition.AttributeName = "neu_taxid";
        condition.Operator = ConditionOperator.Equal;
        condition.Values.Add("012-3456787");
        ColumnSet columns = new ColumnSet(true);
        QueryExpression query = new QueryExpression();
        query.ColumnSet = columns;
        query.EntityName = "account";
        query.Criteria.AddCondition(condition);
        OrganizationServiceClient client = new OrganizationServiceClient();
        EntityCollection collection = client.RetrieveMultiple(query);
        if (collection.Entities.Count == 0)
        {
            _servicePoxy.Create(CreateAccount(agt));
        }
        else
        {
            foreach (Entity contact in collection.Entities)
            {
                //This throws the exception
                _servicePoxy.Update(CreateAccount(agt, contact.Id));
            }
        }
        return string.Empty;
    }

下面是我用来创建传递给Dynamics的Entity对象的方法。数据是从实体框架模型对象中提取的，并映射到相应的字段。

    private Entity CreateAccount(AgentTransmission agt, Guid Id = new Guid())
    {
        _account = new Entity();
        _account.LogicalName = "account";
        _account.Attributes.Add("name", agt.AgencyName);
        _account.Attributes.Add("telephone1", agt.BusinessPhone.Replace("(","").Replace(")", "").Replace("-", ""));
        _account.Attributes.Add("address1_line1", agt.MailingStreet1);
        _account.Attributes.Add("address1_city", agt.MailingCity);
        _account.Attributes.Add("address1_postalcode", agt.MailingZip);
        _account.Attributes.Add("neu_address1stateprovince", LookupStateCode(agt.MailingState));
        _account.Attributes.Add("address1_addresstypecode", new OptionSetValue(1)); //1 for Mailing
        _account.Attributes.Add("neu_channelid", LookupChannelId(agt.Channel));
        _account.Attributes.Add("neu_appointmentstatus", new OptionSetValue(279660000));
        _account.Attributes.Add("customertypecode", LookupCustomerCode(agt.RelationshipType));
        _account.Attributes.Add("neu_taxid", UnobfuscateRef(agt.ReferenceNumber).ToString());
        //If we're doing an update will need the GUID. Only use when Update is needed. 
        if (Id != Guid.Empty)
        {
            _account.Attributes.Add("accountid", Id);
        }
        return _account;
    }

然而，.Create()方法按预期工作，因此我认为异常与我用于更新的accountid GUID属性隔离。