In the Microsoft .NET Framework 2.0, the XML serialization may lose some optional elements in an XSD schema.

This problem occurs because the XMLSerializer class in the .NET Framework 2.0 does not set the public bool field for an optional element during deserialization.

For an optional element, the XML Schema Definition tool (Xsd.exe) generates the following public fields:

• A public field of the corresponding data type
• A public field of the bool type. The name of this field is the name of the element field appended with the "Specified" string.

For example, the name of the element field is StartDate. The name of the public bool field becomes StartDateSpecified.

During deserialization, the XMLSerializer class sets the public field of the corresponding data type for the element. However, the XMLSerializer class does not set the public bool field. This behavior causes the object that contains the optional element to lose the optional element when you serialize the same object back into XML.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

You must have the Microsoft .NET Framework 2.0 installed to apply this hotfix.

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

The Microsoft .NET Framework 2.0, x86-based versions

The Microsoft .NET Framework 2.0, x64-based versions

The Microsoft .NET Framework 2.0, Itanium-based versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Vista Service Pack 1.

After you apply this hotfix, deserialization correctly sets the FieldNameSpecified name of the public bool field on the .NET Framework 2.0 class based on whether the name of the public bool field has the string "Specified" appended in XML.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: