Bob Want has pointed out on the Exchange Team Blog that it can lead to an error if Exchange Server 2010 Service Pack 1 is installed on a multi-role server and then the Client Access and Hub Transport roles are removed. A multi-role server is an Exchange Server that has all 3 Exchange roles (Mailbox, Client Access and Hub Transport role). After removing the Client Access and Hub Transport roles, users are no longer able to use the search function in Outlook and Outlook Web App (OWA). During the uninstallation of the two roles, a symbolic link is removed from the registry, although the Mailbox role is still installed on the server.
Two errors are logged in the server's application event log: 9877 and 9842 both have "MS ExchangeIS Mailbox Store" as their source.
The problem can be solved by executing a PowerShell script. The script and the complete article can be found here:
