My two year old MacBook Pro’s hard drive failed and I took it in to the Apple Store to get it fixed. I’m now running off a backup of my MacBook Pro on the family’s new MacBook Air. All is working as you would expect. But applications purchased from the App Store do not work.

When I attempt to launch an App Store purchase, I am presented with the dialog, “Sign in to use this application on this computer”. Nothing further happens after entering my credentials. Now, every time I click on an App Store purchased app on the dock I get a single bounce and then nothing.

I spoke with Apple support and was escalated one level to no avail. It would seem this is an unsupported configuration although I tend to doubt it’s a driver issue support was hinting at. I stopped them when they wanted to migrate the image to the MacBook Air. This is temporary situation until my production computer is fixed and that exceeds the amount of work I wanted to put into resolving this issue.

Interestingly, App Store purchases downloaded to the MacBook Air’s drive work when launched while booted from my external MacBook Pro drive. Presumably Apple is tattooing the applications with an identifier (Serial Number? Hardware UUID?) from the physical computer that allows me to run the “MacBook Air installed Apps” on my booted MacBook Pro image running the MacBook Air. In the end, not sure if this is a feature or a bug. Support clearly doesn’t understand the mechanics involved. I suspect only an App Store engineer does.

Minutia: Mac OS X Lion 10.7.2 (11C74). When this MacBook Air is booted normally it is attached to the same Apple ID and purchases work.