I also have the problem with initializing EMC. This was an existing Exchange 2010 install with RU4 upgraded to SP1. Server 2008 R2
The following error occured when retrieving user information for Domainadministrator
The operation could not be performed because object 's-1-5-21-4280747840-81974243-757702645-500' couldnt be found on
dc01.domain.com. It was running command Get-LogonUser
CMDlet failed. Cmdlet Get-UserLogon, parameters {Identity=s-1-5-21-4280747840-81974243-757702645-500}
MsExchange Management Event ID 6
I have been trying to find the Cmdlet Get-UserLogon but it is no where on the internet. Perhaps if MS could provide us with this Cmdlet it would fix the problem?