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FIX: The W3wp.exe process crashes when a service operation is implemented asynchronously in a WCF service that is running in ASP.NET 2.0 compatibility mode

View products that this article applies to.


On a computer that has the .NET Framework 3.5 Service Pack 1 (SP1) installed, you host a Windows Communication Foundation (WCF) service in Internet Information Services (IIS). Additionally, you enable the WCF service to run in Microsoft ASP.NET compatibility mode. When a service operation is implemented asynchronously in the WCF service, the IIS worker process (W3wp.exe) crashes.

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This problem occurs because of an error in Microsoft ASP.NET 2.0.

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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.

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, submit a request to 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.


To apply this hotfix, you must have the .NET Framework 3.5 Service Pack 1 (SP1) running on one of the following operating systems:
  • Windows Vista Service Pack 2 (SP2)
  • Windows Server 2008 SP2

Restart requirement

You may have to restart the computer after you apply this hotfix if any affected files are being used when you install the hotfix. Shut down all ASP.NET Web sites before you install the hotfix to avoid having to restart the computer.

Hotfix replacement information

This hotfix does not replace 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.
For all supported 32-bit versions of the .NET Framework 3.5
File nameFile versionFile sizeDateTimePlatform
For all supported 64-bit versions of the .NET Framework 3.5
File nameFile versionFile sizeDateTimePlatform
For all supported IA-64-based versions of the .NET Framework 3.5
File nameFile versionFile sizeDateTimePlatform

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Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

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More information

To run WCF services in ASP.NET compatibility mode, you must include the following configuration in the ASP.NET Web.config file:
<serviceHostingEnvironment aspNetCompatibilityEnabled=�true� /> 
For more information about how to run WCF Services in ASP.NET compatibility mode, visit the following Microsoft Developer Network (MSDN) Web sites:For more information about how to implement a service operation asynchronously in a WCF application, visit the following MSDN Web site:

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Keywords: KB977104, kbqfe, kbsurveynew, kbexpertiseadvanced

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Article Info
Article ID : 977104
Revision : 2
Created on : 10/7/2011
Published on : 10/7/2011
Exists online : False
Views : 41