Microsoft KB Archive/830890

= Call to the ATL __unhook Statement Returns E_FAIL =

Article ID: 830890

Article Last Modified on 10/25/2005

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APPLIES TO


 * Microsoft Visual Studio .NET 2003 Enterprise Architect
 * Microsoft Visual Studio .NET 2003 Enterprise Developer
 * Microsoft Visual Studio .NET 2003 Academic Edition

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SYMPTOMS
If you make a call to the Active Template Library (ATL) __unhook statement, you may receive a return value of E_FAIL.



CAUSE
If you use the __hook statement in an event_receiver(com) object, the __hook statement does not call the AddRef method on the source interface (the second argument to __hook). However, it does store the source interface pointer. This source interface pointer is used later in the call to the __unhook statement. Because there is no reference count, the interface becomes not valid. This behavior causes the call to the __unhook statement to return E_FAIL.



RESOLUTION
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Visual Studio .NET 2003 service pack that contains this hotfix.

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

http://support.microsoft.com/contactus/?ws=support

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.

The English version of this hotfix has the file attributes (or later) 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 tool in Control Panel.   Date         Time   Size    File name --  08-Oct-2003  10:22  13,013  Atlevent.h



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section of this article.



MORE INFORMATION
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the Standard Terminology That Is Used to Describe Microsoft Software Updates

Keywords: kbbug kbfix kbqfe kbhotfixserver KB830890

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