FIX: You experience slow performance or a program stops responding when the program calls a COM method and the MIDL defines an [out] pointer to pointer argument

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When you start a program that makes a call to a Microsoft Component Object Model (COM) method, you may experience slow performance or the program may stop responding (hang).

This problem occurs on the server side when the Microsoft Interface Definition Language (MIDL) defines an [out] pointer to pointer argument.
This problem occurs because the procedure format string that is generated by the type library marshaler incorrectly marks the [out] pointer-to-pointer argument. This behavior causes a memory leak of 24 bytes every time that a COM method call is made.

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.


You must have Microsoft Windows XP Service Pack 2 (SP2) installed to apply this hotfix.

Restart requirement

You must 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 tool in Control Panel.
  Date         Time   Version        Size     File name  ------------------------------------------------------  28-Apr-2005  19:29  5.1.2600.2665  580,608  Rpcrt4.dll 
To work around this problem, use the MIDL-generated marshaler instead of the type library marshaler. To do this, do not use the [oleautomation] attribute for the interface. Then, register the MIDL-generated proxy/stub.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Article ID: 898781 - Last Review: 01/16/2015 16:36:52 - Revision: 4.0

Microsoft Windows XP Professional, Microsoft Windows XP Home Edition

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