Could not discover an OpenID identity server endpoint message when using my StartSSL™ ID. Why is that?
This is typically due to an outdated CA cert bundle being used by libcurl and happens commonly with the Word Press OpenID plugin. Add the StartCom CA root certificate for your server to the existing default CA cert bundle or replace the old ca-bundle with this one. The default path of the CA bundle installed with the curl package is usually /usr/local/share/curl/curl-ca-bundle.crt, but may vary from server to server. On Red Hat based systems this is usually located in /etc/pki/tls/certs/ca-bundle.crt. On Windows this file is usually named curl-ca-bundle.crt.