EMC error: An error caused a change in the current set of domain controllers.
    When opening Exchange Manangemnt Console you get the following error:   An error caused a change in the current set of domain controllers. It was running the command ‘Get-OrganizationConfig’.          In the application log you get the following error entries:   Event ID: 4   Source: MSExchange Configuration Cmdlet – Remote Mamagment   General: Task Get-ExchangeServer writing error when processing record of index 0. Error: Microsoft.Exchange.Data.Directory.SuitabilityDirectoryException: An Active Directory error 0x51 occurred when trying to check the suitability of server ‘dc.mydomain.com’. Error: ‘Active directory response: The LDAP server is unavailable.’ —>