Although the error message isn't the greatest (I will update that). It is trying to tell you that you have entered an incorrect auth key and need to update it. Same as before the auth key is in the portal under 'Demo Manager' -> 'Demo Client'. Simply open the demo manager on your PC, click 'Help' -> 'Auth Key' and enter the correct key.
As for access to all demos - speak to the head admins to see what they would like, if that's fine then I can make the change. Permissions are easily changeable.
Before it was a quick no-authentication/authorisation app that was thrown together, then evolved to have authentication, now finally evolved to have both.