Since Apple decided to stop allowing PPTP, we had to reset our VPN server to use SSL / SSTP. I have set up the server as per the guidelines from Microsoft, however I am unable to connect to the server. I get the following error message: The revocation function was unable to check revocation because the revocation server is offline. I have checked all the services on the server and everything seems to be up and running. In the event viewer I get error 18:
The Secure Socket Tunneling Protocol service either could not read the SHA256 certificate hash from the registry or the data is invalid. To be valid, the SHA256 certificate hash must be of type REG_BINARY and 32 bytes in length. SSTP might not be able to retrieve the value from the registry due to some other system failure. The detailed error message is provided below. SSTP connections will not be accepted on this server. Correct the problem and try again.
The system cannot find the file specified.
I do not know which file it is looking for.