Microsoft KB Archive/249641

From BetaArchive Wiki
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Knowledge Base

Article ID: 249641

Article Last Modified on 10/26/2006


  • Microsoft Exchange Server 5.5 Standard Edition

This article was previously published under Q249641

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry


If you examine the Instances tab in the properties of the public information store and there are over 65,535 public folders, the following error message may be displayed:

An unexpected unknown error has occurred. MAPI or an unspecified service provider. ID no: 80040403-0000-00000000


This issue can occur because the Exchange Server Administrator program relies on MAPI to retrieve information about public folders. MAPI architecture only allows 65,535 rows in a table. If more than 65,535 public folders exist, the table is unable to hold all of the entries and the error message in the "Symptoms" section of this article may be displayed.


To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack


Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4.


After this fix is applied, the Exchange Server Administrator program generates a dialog box that informs you that more than 65,535 public folders exist but only the first 65,535 are displayed. The following is sample text from the dialog box:

Public Folder Instances
Exchange is unable to display more than 64K of public folders.
Folders 1 to 65,535 out of a total of 80,004 are displayed. To change the range of folders displayed you must set a key in the registry.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To add the registry key mentioned in the dialog box:

  1. Start the Registry Editor (Regedt32.exe).
  2. Locate the following key in the registry:


  3. On the Edit menu, click Add Value, and then add the following registry value:

    Value Name: Public Folder Skip Count
    Data Type: REG_DWORD
    Value: number of folders to skip

    This registry value sets the number of public folder entries to skip from the beginning of the list. For example, if the dialog box text indicates a total of 80,004 entries, to display the additional entries set the value to 14469 (80,004 total entries - 65,535 base entries). This allows public folder entries 14,469 through 80,004 to be displayed.
  4. Quit the Registry Editor.

Keywords: kbbug kbexchange550presp4fix kbexchange550sp4fix kbfix kbqfe KB249641