Remote create mailbox on Exchange Server 2013

Hi,

I have an window application (VS 2010) using powershell connection to create mailbox remotely from Exchange Server 2010 without any issue.  After the upgrade to Exchange 2013.  The application throw exception at the line create runspace

"InitialSessionState='runspace.InitialSessionState' threw an exception of type 'System.Management.Automation.PSNotImplementedException' Cannot perform operation because operation "NewNotImplemented Exception at offset 67 in file:line:column<filename unknown>0:0" is not implemented

Does it relate to the WinRM service not running on the exchange server?

Can I use EWS to remotely create mailbox?

Thanks