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Late 2012 Macs Unable to Re-Install OS X or Restore from Time Machine Backups

Late 2012 Macs Unable to Re-Install OS X or Restore from Time Machine Backups

If you’re a proud owner of one of Apple’s late-2012 Macs, including the latest Mac Mini, the new ultra-thin iMacs, and the 13-inch and 15-inch Retina MacBook Pro, you may have a more difficult time than usual re-installing Mountain Lion on your Mac, or restoring from a Time Machine backup.


A strange issue affecting these Macs renders it impossible to re-download the OS X Mountain Lion installer from the Mac App Store, resulting in an error stating that your Mac is not compatible with Mountain Lion (despite the fact that it shipped with Mountain Lion in the first place). Further, if you happen to have the latest version of the OS X Mountain Lion installer on hand, you won’t be able to use it, as the same error is displayed upon launching the installer.

Screen Shot 2013-02-25 at 11.18.32 PM

The issue doesn’t stop at preventing you from downloading or using the downloaded OS X Mountain Lion installer, however – it also prevents you from re-installing Mountain Lion using the Recovery partition. I was able to work around that specific issue by repairing the boot volume permissions immediately before attempting to reinstall, however.

Screen Shot 2013-02-26 at 10.35.44 AM

Worse still, the issue also prevents users from restoring from a Time Machine backup using the Recovery partition. Any attempt to do so results in a message stating “An error occurred while adding a recovery system to the destination disk.” The message directs users to restart their Macs and try again – but unfortunately, restarting does not make a difference in the slightest. Instead of using the Recovery partition to restore from a Time Machine backup, users must use the Migration Assistant app from within a complete OS X Mountain Lion install.


Previously, a seemingly related issue prevented users of late 2012 Macs from updating to OS X Mountain Lion 10.8.2. Apple released Supplemental Update 2 to address the issue – but even with that update installed, the issue persists. This issue is also much broader than the 10.8.2 update issue, as it also affects using the Recovery partition and restoring from a backup.

I’ve verified the issue with my own 27-inch iMac, and made calls to several Apple Authorized Resellers (thanks to the staff at Simply Mac, ExperCom, and Weber State University for assisting with this!), all of whom confirmed that the issue is present on all of their display units of the new 2012 iMacs and Mac Minis. I was unable to verify the issue on the 13-inch and 15-inch Retina MacBook Pro – but I have heard reports that the issue ranges to those devices as well.

Screen Shot 2013-02-26 at 11.03.26 AM

It’s unclear just how long this issue has been present – it may well have existed ever since the affected Macs were first launched. Even reinstalling the OS X 10.8.2 Combo Update fails to address the issue, presenting the same “incompatibility” error. We’ve reached out to Apple for comment, but so far have not received a response. Apple has been testing the OS X 10.8.3 update since November of 2012, which will hopefully address this issue.

It’s concerning that Apple hasn’t managed to patch this apparent long-term issue in the meantime however, leaving their customers in a sticky situation after spending their hard-earned cash on new Macs. Disappointing indeed. I guess spending hundreds or even thousands of dollars simply isn’t enough to ensure that you’ll end up with a product that “just works”…

Update: As of the release of OS X 10.8.3, Apple has officially patched this issue.