You receive an "unable to perform the operation" error message when you save Calendar items in Exchange 2000 and Exchange 2003 (310440)

Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry

SYMPTOMS

When you use Microsoft Internet Explorer to gain access to the version of Microsoft Outlook Web Access (OWA) that runs on Microsoft Exchange 2000 Server or on Exchange Server2003, and you try to save Calendar items, you may receive either of the following error messages:

The action can't be performed.

Unable to perform the operation

Error and warning messages that are similar to the following messages may be logged in the application event log:

Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8219
User: N/A
Description:
The calendaring agent could not publish the free/busy information for "user" because it failed reading the registry with
error: 0x80070002. The save/delete calendar operation for "user" will not be completed. Please ensure that
MSExchangeFBPublish agent is started.

Event Type: Warning
Event Source: EXCDO
Event Category: General
Event ID: 8230
User: N/A
Description:
The calendar of user@company.COM: /Calendar/{2FC3EB8C-5BAC-4060-A64D-F96A934C942C}.EML is corrupted. The recurrence
expansion database for this calendar is being rebuilt. Please view this calendar using Microsoft Outlook Web Access to
complete this operation.

Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8206
User: N/A
Description:
Calendaring agent failed with error code 0x80040215 while saving appointment.

Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8213
User: N/A
Description:
Calendaring agent failed to update the free/busy cache during an appointment save or delete operation.

Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8199
User: N/A
Description:
Calendaring agent failed in message save notification with error 0x800703eb on user@company.COM:
/Calendar/{2FC3EB8C-5BAC-4060-A64D-F96A934C942C}.EML.

CAUSE

This issue can occur if the MSExchangeFBPublish key or its subkeys are missing from the Microsoft Windows registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeFBPublish
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeFBPublish\Parameters
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeFBPublish\Parameters\server_name

The missing value is:

Name: SystemAttendantDN
Type: REG_SZ
Data: /O=Organization/OU=Administrative Group/cn=Configuration/cn=Servers/cn=server_name/cn=Microsoft System Attendant

RESOLUTION

To resolve this issue, restore the correct registry settings on the computer that is running Exchange 2000 Server. To do so, you need to edit the registry.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
To restore the correct registry settings:

On the computer that is running Exchange 2000 Server, start Registry Editor (Regedt32.exe).
Locate and click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
Right-click Services, point to New, and then click Key.
Name the key MSExchangeFBPublish.
Click the MSExchangeFBPublish key, right-click the MSExchangeFBPublish key, point to New, and then click Key.
Name the key Parameters.
Click the Parameters key, right-click the Parameters key, point to New, and then click Key.
Name the key your_server_name, where your_server_name is the name of the Exchange 2000 server.
Select the your_server_name key, right-click the your_server_name key, point to New, and then click String Value. Add the following string value:
Name: SystemAttendantDN
Type: REG_SZ
Data: /O=Your_Organization_Name/OU=Your_Administrative_Group_Name/cn=Configuration/cn=Servers/cn=server_name/cn=Microsoft System Attendant
Quit Registry Editor.

MORE INFORMATION

If you are running in a cluster environment after a failover, you may experience the symptoms that are described in the "Symptoms" section when Exchange is running on its nonstandard cluster node. To resolve this issue, complete the steps in the "Resolution" section on all potential failover nodes.

The registry key that is mentioned in the "Resolution" section is needed on each node of the cluster, and the your_server_name value should be the NetBIOS Exchange Resource name. Therefore, all cluster servers will have the same key.