<<What do you mean Microsoft Session Authentication? Do you mean adding the Identity Sources to SSO?>>
On the main vCenter Web Client logon page there are two windows, one for Username and one for Password. Below those windows is a check box and next to the check box it says, "Use Windows Session Authentication," which is a link. Clicking on this link downloads a plug-in and when installed and the checkbox is checked, the Username ad Password windows get grayed out and I am able to logon to vCenter Server using Windows AD Authentication. However, with the box unchecked and I enter admin@spatialhaze.com in the Username window and the correct Password I entered when setting SSO up, I can not login. That is what I referred to as vCenter Authentication.
I went to the link you left and followed the instructions, except by logging on using Windows AD Authentication and when I go to Administration there is nothing under Single Sign-on Discovery.
Thank you for your assistance,
stmux