So, I installed the WebUI Package onto our Plastic Server (running Server 2012 R2), and I'm assuming I did most of it right.
Our Plastic Server uses Active Directory Authentication, so when deploying the WebUI package, I selected "ADWorkingMode."
Upon completion of the Web Deploy setup of the WebUI package, I am able to see the Plastic SCM WebUI login page.
However, my credentials do not work. It keeps saying that the user name and password are incorrect. (Screenshot attached).