An unhandled exception error has occurred while processing an Active Directory configuration change notification. This error may be caused by network connectivity issues between Active Directory domain controllers and the Unified Messaging server. More information : “%1”.

This Warning event occurs when an Active Directory® directory service configuration change notification request does not process because of an unhandled exception.

During the startup of the Microsoft® Exchange Unified Messaging service, several Unified Messaging (UM) objects are registered by using Active Directory change notification requests. The objects that the UM server tries to register include the following: UM dial plans, UM IP gateways, UM hunt groups, UM server names, and other data. When any of the registered objects are added, removed, or modified in Active Directory, a notification is sent to the UM server which will use the information to perform additional work.

This event may occur for one of the following reasons:

• Network problems cause communications delays between the domain controller and the UM server.

• Errors occur when the UM server tries to retrieve data from Active Directory.

To resolve this warning, do one or more of the following:

• Use the Ping or PathPing command-line tools to test basic connectivity. Use Ping to isolate network hardware problems and incompatible configurations. Use PathPing to detect packet loss over multiple-hop trips. For more information, see Microsoft Knowledge Base article 325487, How to troubleshoot network connectivity problems.

• Review the Application and System event logs for network-card-related events or connectivity-related events. Check the Application log for MSExchangeADAccess and MSExchange Topology events. Use the information in those events to determine the root cause of this warning.

• If this warning frequently occurs, contact Microsoft Product Support. For more information about how to contact support, visit the Microsoft Help and Support Web site.

If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.