Active Directory Certificate Services - "The revocation function was unable to check revocation because the revocation server was offline" - or the world's best error message

I saw this: -

Active Directory Certificate Services denied request 10 because The revocation function was unable to check revocation because the revocation server was offline. 0x80092013 (-2146885613).  The request was for CN=bpm856.uk.ibm.com, DC=uk, DC=ibm, DC=com.  Additional information: Error Constructing or Publishing Certificate

 earlier, whilst trying to issue a SSL certificate using AD Certificate Services: -

certreq -submit -attrib "CertificateTemplate:Webserver"  bpm856.uk.ibm.com_ihs.req bpm856.uk.ibm.com_ihs.cer

As ever, the solution was simple - I merely had to "turn it off and on again"