An inconsistency was detected in %2: file name. The calendar is being repaired. If other errors occur with this calendar, please view the calendar using Microsoft Outlook Web Access. If a problem persists, please recreate the calendar or the containing mailbox.

This Warning event is logged when a problem with a Calendar item is detected. This indicates that Exchange detected data corruption and is trying to rebuild the calendaring data for Web client viewing.

The most common cause of calendar item corruption is scanning the Exchange Installable File System (IFS) drive with file system-based antivirus software. By default, the Exchange IFS drive is drive M. Corruption can also occur when you try to back up drive M. The following articles in the Microsoft Knowledge Base may apply:

305145 How to remove the IFS mapping for Drive M in Exchange 2000 Server

301234 XADM: Calendaring Agent Fails with Error Code 0x80040229 When You Save Appointments

299046 XADM: Calendar Items Disappear from User’s Folders

Other events in the Application log may give you more information about why this event was logged and where the corruption exists. The following events may help you discover the underlying cause of this error:

EXCDO Event 8199: Calendaring agent failed in message save notification with error 0x80040219 on %2: %3.

EXCDO Event 8206: Calendaring agent failed with error code 0x8004010f (MAPI_E_NOT_FOUND) while saving appointment.

EXCDO Event 8206: Calendaring agent failed with error code 0x80040229 while saving appointment.

EXCDO Event 8206: Calendaring agent failed with error code 0x80070057 while saving appointment.

EXCDO Event 8207: Calendaring agent failed with error code 0x8004010f while deleting appointment.

EXCDO Event 8208: Calendaring agent failed with error code 0xfffffae2 while expanding recurring appointments.

EXCDO Event 8217: The processing of the recurring appointment with the subject %1 in mailbox: %2 failed with error code 0x8000ffff. This appointment will not be visible in the web client or other non-MAPI client.

EXCDO Event 8219: The calendaring agent could not publish the free/busy information for %1 because it failed reading the registry with Error code 0x80070002. The save/delete calendar operation for %2 will not be completed. Please ensure that MSExchangeFBPublish agent is started.

EXCDO Event 8241: An existing appointment with the subject %1 in mailbox %2 was modified. The start time, or both the duration and end time of the existing appointment were missing.

EXCDO Event 8243: The calendaring agent cannot bind to the appointment with the subject %1 in mailbox %2 because the appointment is missing a start time. The calendaring agent will not publish free/busy information for this appointment. To correct this, please delete the appointment and recreate it.

EXCDO Event 8255: The background calendaring agent failed to logon to the MDB, or create a session object on the MDB:%1. The error code is 0x000003ef. The rendering of large calendars with the web client or Microsoft Internet Explorer for the mailbox %2 with GUID:%3 will be slower.

EXCDO Event 8263: The recurring appointment expansion in mailbox %1 has taken too long. Some recurring appointment instances may not be visible at this time. To ensure that the calendar view is correct, please refresh the calendar view in Microsoft Outlook Web Access.

To resolve this error, try one or more of the following:

• After Exchange rebuilds the data, verify whether Exchange was able to correctly display the calendaring data on the Web client.
• Examine the Application log for relevant EXCDO source event messages. These events may provide additional information about the underlying issue.
• Make sure that a file system-based antivirus program running on the Exchange Server is not scanning the Exchange IFS drive (M drive). Additionally, make sure that any backup software used is not backing up the Exchange IFS drive. If the corruption cannot be isolated or corrected, restore the data from a backup. For more information, see the Microsoft Knowledge Base articles referenced earlier in this article.