Exchange Server 2010 SP2 Upgrade Client Access Role Failed. "Update-OwaVirtualDirectory... Object reference not set to an instance of an object"

Hi,

I've hit a number of failures and error along the way with installing Exchange 2010 on Server 2008R2. I've found fixes online but can't find a fix for this error. Please see screenshots. Note Exchange with SP1 was installed and I am now trying to install SP2