The attempt to connect to http://exchange.contoso.com/powershell using 'Kerberos' authentication failed:

[hmi]

Resolutions:

Method 1:
1.Close all MMC/EMC instances before proceeding.
2.Open Registry Editor (regedit) as the user you run the EMC under.
3.Go to HKEY_CURRENT_USER\SOFTWARE\Microsoft\ExchangeServer\v14\AdminTools
4.Look for value NodeStructureSetting.
5.If it is there, back it up and then remove it.

Method 2:
1.Close all MMC/EMC Instances before proceeding.
2.Open Powershell or Powershell IDE as the user you run the EMC under and execute the following command:.
3.Remove-ItemProperty -Path HKCU:\Software\Microsoft\ExchangeServer\v14\AdminTools\ -Name NodeStructureSettings
4.Close Powershell

After performing either of the methods above to remove the registry entry you should be able to open the Exchange Management Console and it will discover another Exchange server and connect.