Synchronous plug-ins do not respond to the events that are triggered in Microsoft Dynamics CRM 4.0

When you deploy synchronous plug-ins in a Microsoft Dynamics CRM 4.0 server that is configured to use a host header, the synchronous plug-ins do not respond to the events that are triggered in Microsoft Dynamics CRM 4.0.

Errors that resemble the following may be seen in event viewer and platform traces:

• Stack Trace Info: [WebException: The request failed with HTTP status 400: Bad Request.]
  at Microsoft.Crm.Extensibility.SdkTypeProxyCrmServiceWrapper.InternalInvoke(MethodInfo methodInfo, Object[] parameters)
  at Microsoft.Crm.Extensibility.SdkTypeProxyCrmServiceWrapper.Execute(Object request)
  
• System.Net.WebException: The request failed with HTTP status 404: Not Found.
  at Microsoft.Crm.Extensibility.PluginStep.Execute(PipelineExecutionContext context)
  at Microsoft.Crm.Extensibility.Pipelin.Execute(PipelineExecutionContext context)

This problem occurs because the URL of the CrmService object in the Software Development Kit (SDK) proxy resembles the following URL: Therefore, Microsoft Dynamics CRM 4.0 does not handle the host header correctly.

This problem is fixed in the latest cumulative update rollup for Microsoft Dynamics CRM 4.0. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
Additionally, create a LocalSdkHost registry key on the Microsoft Dynamics CRM 4.0 server. To do this, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM
3. Right-click MSCRM, click New, and then click String Value.
4. In the Name box, type LocalSdkHost.
5. Right-click LocalSdkHost, and then click Modify.
6. In the Value box, type the name of the Microsoft Dynamics CRM server or the host header, and then click OK.
   
   Note Do not specify http:// or the port number.
7. Locate the LocalSdkPort key at the same location. Verify that the port that is listed matches the port that is being used for the CRM Web site.
8. If the value of the LocalSdkPort key is incorrect, right-click LocalSdkPort, and then click Modify. Type the correct port number, and then click OK.

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

For more information about the terminology that is used to describe Microsoft software updates, click the following article numbers to view the articles in the Microsoft Knowledge Base: