OMG! I can't believe it! We accidently stumpled across the solution! I wanted to post it just in case anyone else had this same problem (or had this same "Blonde" moment. YES; I am blonde so I can say that!!)
The "Authinticate" information that was being requested was the Mac user ID & Password to allow the installation!!
In my defense; the window didn't look the same as it does when asking for the ID & Password to allow system updates.