ADFS : The remote certificate is invalid according to the validation procedure

So playing around with the proxy and using self-signed certificates and get the above error.

WTF?

So Mr. Google to the rescue and there’s much discussion about disabling the chain revocation checking on the certificate on the ADFS server. This can be done through the PowerShell commands.

But there doesn’t seem to be a command to do this for the proxy.

So pull hair out and then found an entry that suggested that the key was to import the certificate of the ADFS server to the proxy but import it to the Computer Account instead of the “my user” aka “personal” aka “local” account.

Job done!

Enjoy!