On a computer that is running Microsoft Office Communications Server 2007 R2, you search for a user in the Active Directory Users and Computers Microsoft Management Console (MMC) snap-in. When you try to click the Communications tab in the Properties dialog box of the user for whom you searched, the snap-in crashes.
To resolve this issue, apply the following update:
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
971289 Description of the update package for Office Communications Server 2007 R2, Administration Tools: July 2009