Salesorder Fulfill state

I was trying to catch the Fulfill state of sales order and my try was successful, with registering plugin to Update message at Child pipeline. But there was a one little problem - you can't get the salesorderdetail thru service. I don't know why, but the simple code like in "Example 1" was falling down with Generic SQL error x80044150.

//  Example 1
QueryByAttribute qba = new QueryByAttribute();
qba.EntityName = EntityName.salesorderdetail.ToString();
qba.ColumnSet = new AllColumns();
qba.Attributes = new string[] { "salesorderid" };
qba.Values = new object[] { soid };
BusinessEntityCollection bec = crmService.RetrieveMultiple(qba);

Then I was switch on the Fulfill Sdk Message and everything start working fine!

1. open up the SdkMessage view, filter by Name and find the SdkMessageId
2. open up the SdkMessageFilter view, filter by SdkMessageId you got from step 1.
3. change IsCustomProcessingStepAllowed to 'True'

update dbo.SdkMessageFilter
set IsCustomProcessingStepAllowed=1
where SdkMessageId=
(select top 1 SdkMessageId from dbo.SdkMessage where name ='Fulfill')

I have a question, why the Fulfill message has been unplugged from customization?