XADM: Unable to Expand Public Folder Hierarchy

When you attempt to open the Public Folders or System Folders containers in the Microsoft Exchange Server Administrator program, the following error message may be displayed: In Microsoft Outlook, when users attempt to expand the public folder hierarchy, the users may receive the following error message:

This issue can occur if the Exchange Server computer that you are connected to in the Administrator program points to another server as the public folder server, and the Public Information Store object has been removed from the Administrator program of that other server.

To resolve this issue:

1. In the Private Information Store properties of the server that is receiving the error message, click the General tab, and then click to select the Public folder server check box. This check box is most likely clear.
2. Click another server in the list, and then apply this change.
3. After you make the change, quit and then restart the Administrator program.