How to Recover Data after Failed macOS Sierra Upgrade

Summary: The objective of this blog post is to share useful MacOS Sierra data recovery information when your Mac fails to upgrade to macOS Sierra and doesn’t boot to any OS X due to failed installation procedure.

Apple always recommends backup the entire Mac hard drive through Time Machine application before upgrading to a latest OS X. Moreover, Apple keeps the OS X update process very simple so that every user can upgrade to a newer version without the assistance of an Apple expert. Despite all these measures, many Mac users come across data recovery problems either during the OS X upgrade processes or after the OS X installation. Data losses while an OS X upgrade isn’t limited to any specific Mac devices, but it can occur on an iMac, MacBook Pro, Air, Mini or Pro.

A failed OS X installation wouldn’t affect a pro-active Mac user who readily backs up everything to a Time Machine drive. Even if the Mac fails to boot to an OS X, the user can still boot into Recovery Mode and choose the option “Restore from Time Machine Backup” which will restore the previous version of OS X with all data back to the user’s Mac. It’s that simple!!

Let us consider an example. Mr Patrick didn’t take backup of his Mac system and went forward to upgrade to macOS Sierra. During the operation, the Mac rebooted and showed Mr Patrick the error “OS X Sierra couldn’t be installed on your machine”.

In the absence of a Time Machine backup copy, rolling back to the previous OS X and restoring data becomes a dream. Every time, he restarts his Mac, the monitor greets him with the same error “OS X Sierra couldn’t be installed on your machine”.

Solution (As recommended by Apple)

Step 1) On the event of encountering the error mentioned above, Apple recommends to backup and format the targeted hard disk drive. If you can back it up without any issues, then the problem will be solved. But,

Step 2)If the hard drive couldn’t be backed up, then you must perform a small surgery to resolve this issue. Please follow below advice:

Bootable Mac Data Recovery

The above solution recommended by Apple may work out for your problem. However, in case, you couldn’t fix the issue of a failed OS X upgrade and data recovery, then Stellar Phoenix Mac Data Recovery with Recovery CD could be your last option to boot the non-bootable Mac and perform data recovery on your startup disk. The mentioned application is capable of recovering erased, deleted and lost files from Mac boot drive, local volumes, Time Machine external hard drive, an encrypted drive and from a disk image file. Hence the application will offer plenty of robust features such as Deleted Recovery, Advance, RAW Recovery to locate all inaccessible, lost or deleted files from startup disk drive.

MacOS Sierra Data Recovery (Process)

Step 1) Open the software interface and select the MacOS Sierra startup disk drive from the left corner. Now, from the list of available data recovery options, choose a data recovery mode (Recover Data, Deleted, RAW Recovery etc.). Continue to start scan.


Step 2) After the completion of the scan, the recovered data and folders are listed in tree for your preview.


Step 3) Select the recovered folders and click Recovery button to save them on an external hard drive. Note: Software saves the recovered data to a chosen destination after the registration is completed.



The problem of data loss and recovery after a failed macOS Sierra could get resolved by resizing the startup disk drive or with the help of the mentioned utility which will boot up the Mac for file recovery.


  1. Travis Bruce December 26, 2016
  2. Roy Edwards December 26, 2016
    • Tom Patrick December 26, 2016
  3. Dunagan January 2, 2017
    • Tom January 2, 2017
  4. Lena Valdez January 30, 2017
    • Tom Patrick January 30, 2017
  5. Allyson Lkard February 21, 2017
    • Tom Patrick February 21, 2017

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