FIX: An application that is based on the Microsoft .NET Framework 2.0 Service Pack 2 and that invokes a Web service call asynchronously throws an exception on a computer that is running Windows 7

On a computer that is running Windows 7, you experience one or more of the following symptoms.

Symptom 1

Consider the following scenario:

• You run an asynchronous Web service that uses the Microsoft .NET Framework 2.0 Service Pack 2 (SP2) on a server.
• 
  The HttpWebRequest asynchronous operation sends a Web request to the Web service.
  
• The Web service throws an exception.
  

In this scenario, the HttpWebRequest asynchronous operation does not call the BeginGetResponse method or the callback function. However, the HttpWebRequest asynchronous operation is unexpectedly completed. The Web service then stops responding. Additionally, the CPU usage on the server may increase to 100 percent, and then the server stops responding.

Symptom 2

Consider the following scenario:

• You run a Microsoft .NET Framework 2.0 SP2-based application that calls a Web service by using the Microsoft ASP.NET Web service client components. For example, the application code is generated by the Wsdl.exe process, or the application calls the SoapHttpClientProtocol class.
• The client invokes the Web service call asynchronously.
• The client sends a request to a server.
• The client then receives a Web response that has zero-length content.

When the Web service tries to process this response in this scenario, a System.ArgumentNullException exception is thrown. Then, you receive the following error message:Note This problem does not occur when the client invokes the Web service call synchronously.