Sign In Required when using Classic/2015 installer

I'm trying to deploy Acrobat Standard DC.

I logged into the licensing site and downloaded Acrobat_2015_Web_WWMUI.exe (description: Acrobat DC2015 12.0 WIN ESD ALL CLASSIC )

I downloaded the Acrobat Customization Wizard DC

I wrote down the serial number from the licensing website for Acrobat 12.0 Universal English Windows LIC SN

In the CustWiz "Personalization Options" I entered the serial number (copied & pasted to make sure there were no transposition errors)

In the CustWiz "Online services and features" I checked Disable Product Updates, Disable Upsell and Disable all services

I saved the package, which created AcroPro.mst

I also did transform>generate transform and called it myInstall.mst

I've then deployed acropro.msi with TRANSFORMS="AcroPro.mst" (and also tried with MyInstall.mst) and it successfully installs the program.

I double-checked that the path is C:\Program Files (x86)\Adobe\Acrobat 2015\ which signifies the Classic track installer

When I try to launch Adobe Acrobat DC, I'm prompted that Sign In is Required...

According to the ETK Pre-deployment planning, granting usage rights section, it says that "Admin pre-activates for all users"

Does that mean entering the serial number in the Customization Wizard (which I've already done) or is there some other thing I have to do to activate that license/serial number so that I can avoid this whole sign-in thing and run Acrobat DC just like we have in the past?