After renewing expired certificate, some client computer may have issues to connect to SSTP VPN. Following error message comes up
“The revocation function was unable to check revocation because the revocation server was offline”

This problem seem to be related to caching which can be cleared by either restarting client computer or by going into internet options, Content Tab, then click on Clear SSL state

If after restarting computer, problem still exist, temporary fix would be to disable revocation check from the registry.

Steps

1. 1. Go to HKLM\SYSTEM\CurrentControlSet\Services\SstpSvc\Parameters
   2. Add DWORD NoCertRevocationCheck
   3. Set it’s value to 1