How to Recover Lost Data after macOS High Sierra Upgrade or Downgrade?

2017-11-28 22:34:09 / Posted by Peter William to Recover Follow @ Peter

How can I recover lost data after upgrading from El Capitan to macOS High Sierra? Yesterday I upgraded my Mac OS from 10.11 EI Capitan to the macOS High Sierra. However, some documents were missing after update. And I don’t have a Time Machine backup. How can I get them back? - From Carter.

MacOS High Sierra which brings some important changes to the way you use your Mac was released in September. And many Mac users have lost their photos, videos and other documents during or after upgrading Mac to macOS High Sierra. However, data loss which makes you upset is one of the most common problems after macOS High Sierra upgrade. Actually, downgrading from macOS High Sierra to El Capitan also could cause data loss. Here below, you’ll find effective solutions to recover lost Mac data after macOS High Sierra upgrade or downgrade.

Before you get all your lost data back, you should not put new data to your Mac in case that the lost files would be overwritten by new data. If you will update to macOS High Sierra, please make a full preparation before updating to macOS High Sierra. Thus you will minimize data loss possibility.

Recover lost data after macOS High Sierra upgrade or downgrade from Time Machine backup

If you have created Time Machine backup before macOS High Sierra upgrade or downgrade, you can restore lost or missing data from Time Machine backup.

  1. From the Apple menu, select System Preferences, then choose the Time Machine icon. Select the “Show Time Machine in menu bar” checkbox.
  2. Choose “Enter Time Machine” from the Time Machine menu. You'll be taken to the Time Machine window. Then you can navigate to the file or folder you'd like to restore.
  3. Select a file and press Space Bar to preview the file. Find the one you need to recover and click Restore to restore the selected file, or Control-click the file for other options. Time Machine will copy that file back to its original location on your hard disk.

You can also use the timeline on the edge of the screen to see the files in your Time Machine backup as they were at that date and time and use the onscreen up and down arrows to jump to the last time the contents of the window changed.

Recover missing data after macOS High Sierra upgrade or downgrade directly from Mac

If you haven’t created any backups for your Mac data and you lost it after updating to new macOS High Sierra or downgrading to El Capitan, then you’ll need to follow below guidance to recover them without backup.

  1. Acquire a professional Mac data recovery tool
    Is it difficult to recover lost data without backup after upgrading to macOS High Sierra? No, it is very simple and all you need is professional Mac data recovery software like Cisdem Data Recovery for Mac. It fully supports OS 10.8 or later including the newest Mojave, Sierra, EI Capitan, and Yosemite etc.
    Cisdem Data Recovery allows you to restore all lost data from Mac hard drives or other external storage devices within 3 simple clicks. Office files, photos, music, videos, emails, packages or other archives can all be restored on your own. And you can download this data recovery software to try and see what can be recovered by it.
     Free Download
  2. Select a recovery mode
    Install and launch Cisdem Data Recovery, and you will see five recovery solutions including Basic Data Recovery, Trash Recovery, Formatted Drive Recovery, External Devices Recovery and Advanced File Recovery.. Choose the one which is suitable for your situation. Then it will navigate to next interface.
  3. Choose the hard drive to scan
    This data recovery will automatically list all Mac hard drives and storage devices if connected to your Mac computer. Select the hard drive where you lose the data. Then click “Scan” to start scanning lost data from the selected hard drive. It will take a short moment to complete the scanning process depending on the amount of files it is scanning through.
  4. Preview and recover lost data
    After scanning, you can preview and recover the lost files. To quickly find the files you want to view or recover, you can enter the keywords to the Search Box at the top of the list. On the top right of the interface, three modes including List, Thumbnail and Preview are also provided to let you view the discovered lost files. 
    Then select the files you want to recover and click “Recover” to get them back on your Mac. After finishing recovery, the Show in Finder button allows you quickly locate to the folder that stores all recovered files.

In macOS 10.13 High Sierra, a significant feature called "System Integrity Protection" (SIP) is introduced and enhanced, which prevents malware from modifying protected files and folders on Mac.

SIP also intervenes when third-party safe apps are trying to gain access to system disk or partition. So before you use Cisdem Data Recovery that is 100% safe and clean to perform data recovery under macOS 10.13, you need to temporarily disable SIP.


How to Temporarily Disable System Integrity Protection?

Step1. Reboot the Mac and hold down "Command + R" keys simultaneously after you hear the startup chime.

Step2. When the "macOS Utilities" screen appears, click "Utilities" in the menu bar, and choose "Terminal".

Step3. In the "Terminal" window, type in "csrutil disable" and press "Enter" then restart your Mac.

And you can also turn on SIP after recovering data on macOS High Sierra. To enable SIP, just follow above steps and type in "csrutil enable" in Terminal.


Upgrading to a new OS might wipe out your data completely. Another option that you can consider is to partition your hard drives and opt to install the new OS in one of the partitions. Even though you can rely on powerful data recovery software like the Cisdem Data Recovery for Mac, make it a habit to back up your Mac in order to be prepared for any data loss situations.

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2 Comments Leave a Reply

  • Jooye

    I found many files missing after mac os sierra upgrade, and I didn't backup them to somewhere, I tried this data recovery, it found them on my Mac hard drive, thanks a lot.

    2 years ago REPLY
  • Tonyer

    Losing data after mac os upgrade or downgrade is not very much common if the user operate correctly I think. But it is indispensable to always keep a data recovery in hands. I do have one.

    2 years ago REPLY