Migrated users get an unable to display the folder error when trying to access other users' calen (NETIQKB34170)

fact
Exchange Migrator 2.x

symptom
Error: 'Unable to display the folder' received by migrated users trying to access other users' calendars.

cause
The is a known issue with Microsoft.  Access to another user's calendar requires that you also have corresponding permissions to the users FreeBusy Data folder.

fix

To resolve this problem, you can use the ACL object to also set permissions on the FreeBusy Data folder. This folder is located at the root of the Microsoft Exchange Server mailbox and does not display in the Outlook client. If you grant read-only access to the calendar, set the same access level to the FreeBusy Data folder. If you grant write access to the calendar, you must grant editor-level permissions to the FreeBusy Data folder.

You can now access the Calendar folder with Outlook 2000 without an error.   For more information about this error, please refer to the following Microsoft Knowledge Base article:

Outlook 2000 Doesn't Properly Read ACL Settings: 237924

Formerly known as NETIQKB34170