OAuth2+ OpenID Connect SSO I am trying to implement the OpenID Connect SSO as outlined in Nik Vahalik’s YouTube video and in Patrick Dawkins’ Tutorial.  I have gone step by step through their implementation instructions as well on the documentation page (https://www.drupal.org/node/2274367).  

I have the OAuth server running on one Drupal Instance.  I have the client login setup on a different Drupal Instance.  I have the sso.php located in the root of each Drupal instance.  

When I click “Login with Generic” on the client site, I get an error that says “Not Found The requested URL /oauth2/authorize was not found on this server.”
The URL bar shows this as its attempted destination:
https://devcondrupal.genieve.com/oauth2/authorize?client_id=devdrupalclient&amp;response_type=code&amp;scope=openid%20email%20profile&amp;redirect_uri=https%3A//devdrupal.genieve.com/%3Fq%3Dopenid-connect/generic&amp;state=7a4e2dc4a66e3aa3b4531b5d523f6371

I am using self-signed SSL certificates on both the OAuth Server site and on the Client site.

I don’t know where to begin troubleshooting the issue as this is my first experience with OAuth / OpenID and there is not much information out there on the web (Drupal-wise).

Thanks for your help.
It turns out that "Clean URLs" need to be turned on for OpenID...  I added "AllowOverride All" to the  section under VirtualHost in my Apache config file.  This allowed me to turn on Clean URLs and the error is now gone.