Alright about a week and a half ago my Macbook Pro started acting up. All of my applications were crashing randomly and what not so I decided to just try and reinstall El Capitan onto it. I tried and tried and tried but only got an error about how it couldn't be installed on that computer.

So then I went and completely reformatted my hard drive and booted up with Internet Recovery. Told it to install Mac OS X Lion again (that's what came with my computer) and I am now getting the following errors when I look at the installer log:

Line 1: Install Mac OS X Lion [379]: Chunk validation failed, retrying...

Line 2: Failed to verify InsallESD.dmg: hdiutil verify failed

Line 3: Damaged resume data :/Volumes/Samsung SSD 850 EVO 250GB Media/Mac OS X Install Data/InstallESD.dmg.partial : /Volumes/Samsung SSD 850 EVO 250GB Media/Mac OS X Install Data/InstallESD.chunklist.partial

I'm leaning towards the conclusion that my SSD has gone bad even though it's only a little over a year old.

However, I thought I would post here too in case anyone else has had this problem and was able to fix it without getting a new hard drive.

It's also worth noting that when I use Disk Utility to check the disc for errors it doesn't find anything.


I just tried to install onto my old mac hard drive and I'm getting the same error. After some more research I saw that some say if you upgraded ram to take out the ram from one of the slots and try again. I'm going to try that when I get home and see if that works.


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.

Here's an article that will help you locate and remove any RAM that you may have previously installed in case someone else had done it for you or before you.

MacBook Pro: How to remove or install memory

  • 2
    I have been trying, usb boot, internet download, but with no luck for days. Thank you so much. I would have never guessed it was the upgrading of the RAM causing this. The installation got through this time with no problems. Thank you again for pointing me to the right direction.
    – Ayoub
    Aug 27 '17 at 12:39
  • @Ayoub No problem! Glad I was able to help! :)
    – Quiver
    Aug 28 '17 at 17:12
  • I really did not think this would work but it did - cheers!!! Feb 7 '19 at 21:39
  • A bit unfortunate that you wiped your ssd before finding this, but better late then never!
    – Sam
    Feb 7 '19 at 21:44
  • I bought a Mac Mini off eBay that had two sticks of 4GB RAM and it presented this same issue validating installESD.dmg. The first stick looked unbranded and cheap and I removed it, revealing what looked to be a stick of stock RAM from Apple. Removing the one stick resolved the issue for me.
    – Cory Klein
    Oct 4 '19 at 23:17

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