Note the "Exchange SP2 or SP3" at the top of this article

I was having major Exchange Powershell issues with Exchange SP1 installed - running "New-ExchangeCertificate" even on it's own gave a "Error 0xe0434f4d"Updating to Exchange SP3 fixed this immediately. I could not find any information on the Powershell errors. Hope this saves someone some time.Thansk, Rob