Firstly, i have this problem too. Secondly, gyrhead seems to have two contradictory suggestions, but perhaps I am missing a nuance. Oh - now i see (after writing the rest of this message). The preference setting i found requires and Apple ID, and i think it must be a special VPP program apple ID? Didn't know what "log into configurator" -- but i think understanding those two messages is key. Will re-read the docs.
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I have logged into iTunes and alunched the configurator from one computer, downloaded a free app, then attempted to use configurator from THAT mac to intitialze a set of iPads in a Bretford tray.
I think this means i must have authorized this computer for that apple ID. I even tried authorizing the ipads by connecting them to the store and downloading free apps, and set authorized them for the same app id.
I see that configurator itself has preference seting for apple ID, and it says "The Appl eID used in the Itunes Store on this Mac to redemm VPP redemption codes and download apps. This is not the VPP PRogram Facilitator's Apple ID." I know this is not a VPP Program Facilitator's Apple ID; i am not sure if this means i Should use the VPP Program Facilitorto's Apple ID or if this means that it SHOULD NOT be as it won't be used that way.
In any event i just want to install and manage FREE apps, and don't have a VPP Program account.
With one regular Apple ID intended for use with free apps, i can't make this work.