I have a Early 2011 MacBook Pro and I've been wanting to give it away (as it is acting up) so I factory reset it. Erasing the hard disk went fine, but when I tried to reinstall the OS in the recovery mode, it keeps showing errors and not letting me restart. It says

  • no native mechanism to verify basesystem.dmg,

  • no native mechanism to verify applediagnostics.chunklist


  • failed to verify installESDDmg.pkg: xar_verify failed

in the installer log. It also remains stuck on the same screen with about a minute remaining....

How do I resolve this issue?

1 Answer 1


The pulling the RAM out before installing did the trick for me!

When I first bought my MacBook 5 years ago it only came with 4GB of RAM. About a year and a half ago I upgraded this to 8GB. For whatever reason this throws errors and won't let you reinstall Mac OS X again.

So what I did was turned the MacBook off and flipped it over and took off the bottom cover. I then removed one of the sticks of RAM (the one on top) and restarted the computer and tried installing again. This time it installed without any issues and after it was installed I put the other stick of RAM back in again.

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