We installed the Quest ActiveRoles Management Shell for Active Directory 1.5.1 on our terminal server and suddenly our Exchange Management Shell is broken with this error: ========================================================== Exception calling "GetComputerSite" with "0" argument(s): "Configuration system failed to initialize" At C:\Program Files\Microsoft\Exchange Server\V14\bin\ConnectFunctions.ps1:164 char:92 + $localSite=[System.DirectoryServices.ActiveDirectory.ActiveDirectorySite]::GetComputerSite <<<< () + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : DotNetMethodException The following exception was thrown when trying to enumerate the collection: "Configuration system failed to initialize" . At C:\Program Files\Microsoft\Exchange Server\V14\bin\ConnectFunctions.ps1:253 char:17 + $search.FindAll <<<< () + CategoryInfo : NotSpecified: (:) [], ExtendedTypeSystemException + FullyQualifiedErrorId : ExceptionInGetEnumerator You cannot call a method on a null-valued expression. At C:\Program Files\Microsoft\Exchange Server\V14\bin\ConnectFunctions.ps1:146 char:33 + $siteName = $siteDN.ToString <<<< ().SubString(3).Split(",")[0] + CategoryInfo : InvalidOperation: (ToString:String) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull WARNING: No Exchange servers are available in the Active Directory site . Connecting to an Exchange server in another Active Directory site. Failed to connect to an Exchange server in the current site. Enter the server FQDN where you want to connect.: ========================================================== We have since uninstalled the Quest add-in but with no success.... Our environment is as follows: We have 1 root domain and 2 sub domains (Site A and B). Site A: Exchange 2003 Site B: Exchange 2010 Our terminal server (Site A, Ex 2k3) is managing Exchange 2010 on Site B. This worked flawlessly prior to the quest install. Please help Thanks in advance...SMGrow