"Folder Root was not found" Exchange Synchronization error occurs during User Synchronization phase.

SYMPTOMS

The following messages are logged at ERROR and FATAL levels during User Synchronization phase: 

ERROR ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.EwsFolderManager - Folder Root was not found in <EMAILADDRESS@DOMAIN.COM>:
Microsoft.Exchange.WebServices.Data.ServiceResponseException: The account does not have permission to impersonate the requested user.
 at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ProcessWebException(WebException webException)
 at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.GetEwsHttpWebResponse(IEwsHttpWebRequest request)
 at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ValidateAndEmitRequest(IEwsHttpWebRequest& request)
 at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.Execute()
 at Microsoft.Exchange.WebServices.Data.ExchangeService.BindToFolder[TFolder](FolderId folderId, PropertySet propertySet)
 at Microsoft.Exchange.WebServices.Data.Folder.Bind(ExchangeService service, WellKnownFolderName name)
 at ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.EwsFolderManager.GetFolderWithSubfolders(WellKnownFolderName wellKnownFolder, Boolean ignoreErrors)

FATAL ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.ExchangeSynchronizer - Error while synchronizing deleted items for account <EMAILADDRESS@DOMAIN.COM>
Microsoft.Exchange.WebServices.Data.ServiceResponseException: The account does not have permission to impersonate the requested user.
 at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ProcessWebException(WebException webException)
 at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.GetEwsHttpWebResponse(IEwsHttpWebRequest request)
 at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ValidateAndEmitRequest(IEwsHttpWebRequest& request)
 at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.Execute()
 at Microsoft.Exchange.WebServices.Data.ExchangeService.BindToFolder[TFolder](FolderId folderId, PropertySet propertySet)
 at Microsoft.Exchange.WebServices.Data.Folder.Bind(ExchangeService service, WellKnownFolderName name)
 at ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.EwsFolderManager.GetFolderWithSubfolders(WellKnownFolderName wellKnownFolder, Boolean ignoreErrors)
 at ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.EwsFolderManager.FillAvailableFoldersTree()
 at ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.EwsExchangeWebService..ctor(ExchangeConnectionSettings connectionSettings)
 at ZyLAB.EDiscovery.Exchange.Standalone.ExchangeSync.ExchangeSynchronizer.SyncUserMailboxDeletionsWorker(CancellationToken token, BlockingCollection`1 emailAccounts, Boolean onlySyncExistenceStatuses)

CAUSE

The credentials used to run User Synchronization have not been granted permissions to impersonate the reported user(s).

RESOLUTION

The credentials used to run User Synchronization should have impersonation permissions for all users within the scope of Exchange Synchronization.

To confirm that this is the case, it is helpful to use EWS Editor from Codeplex, a Microsoft open source project (http://ewseditor.codeplex.com/).

To solve this issue, Impersonation configuration should be rectified on the Exchange environment.
The New-ManagementRoleAssignment, New-ManagementScope, Set-ManagementRoleAssignment, or Set-ManagementScope Powershell cmdlets can be used to set Impersonation.

Configure Exchange Server 2010 Impersonation
https://technet.microsoft.com/en-us/library/ff793352%28v=office.14%29.aspx

ApplicationImpersonation role
https://technet.microsoft.com/en-us/library/dd776119%28v=exchg.150%29.aspx

APPLIES TO

3.7; 3.7 Service Pack 1