This Error event indicates that the Microsoft Exchange System Attendant service failed to obtain a list of available global catalog servers from Active Directory. This event may be caused by network problems between the Exchange server and the configuration domain controllers it uses. Exchange will continue to use the global catalog servers of which it is currently aware.

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

• Use the Netdiag tool to verify network connectivity between the Exchange server and the domain controllers it uses. For more information, see Netdiag.
  
  
• Use the Dcdiag tool to verify that the Exchange server can communicate successfully with Active Directory. For more information, see Dcdiag.
  
  
• Resolve your issue by using self-support options, assisted support options, and other resources. You can access these resources from the Exchange Server Solutions Center. From this page, click Self-Support Options in the navigation pane to use self-help options. Self-help options include searching the Microsoft Knowledge Base, posting a question at the Exchange Server forums, and others. Alternatively, in the navigation pane, you can click Assisted Support Options to contact a Microsoft support professional. Because your organization may have a specific procedure for directly contacting Microsoft Technical Support, be sure to review your organization's guidelines first.
  
  

If you are not already doing so, consider running the Exchange tools created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.