Microsoft KB Archive/327351

= FIX: You Cannot Edit a DataRow in a Child Table if the DataSet Is Constructed from XML DiffGram =

Article ID: 327351

Article Last Modified on 9/27/2005

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APPLIES TO


 * Microsoft .NET Framework 1.0
 * Microsoft .NET Framework Service Pack 1
 * Microsoft .NET Framework Service Pack 2
 * Microsoft ADO.NET 1.0

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This article was previously published under Q327351





SYMPTOMS
When you edit a child table row in a DataSet, you may receive the following error message.

Object reference not set to an instance of an object. (91)

This error occurs when the following conditions are true:
 * The DataSet was contructed from XML that was persisted with changes in DiffGram format.
 * The child table columns have expressions that are based on the parent table columns.



CAUSE
The construction of the DataSet is incorrect when there is a master-detail relationship between the tables in the persisted DiffGram XML.



RESOLUTION
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Note that this fix requires that you install Microsoft .NET Framework 1.0 Service Pack 2 (SP2) or later on the system. The English version of this fix has the file attributes (or later) that are listed in the following table.

  Date           Version       Size       File name 08-SEP-2002   1.0.3705.357  1,179,648  System.Data.dll 08-SEP-2002   1.0.3705.357  1,986,560  System.Windows.Forms.dll 08-SEP-2002   1.0.3705.357     16,744  System.Windows.Forms.ldo 08-SEP-2002   1.0.3705.357     57,344  System.Windows.Forms.tlb



WORKAROUND
Remove the expressions, and then programmatically populate the values of the derived columns through a constraint or event in the DataSet.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

Keywords: kbbug kbfix kbqfe kbhotfixserver KB327351

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