mac-appstoremacosupgrade
I can’t find the installer and presume Apple deleted the Mac OS Sierra installer from the app store search as well as our collective purchased apps pages.
I'm running Sierra at the moment, and I upgraded from lion.
How can I get the previous Sierra installer now, in case my update to High Sierra goes wrong?
This works for both iTunes Apps and the App Store on the Mac.
Items aren't deleted from the list, just merely hidden.
Whether or not you've downloaded it in the past, you can now download OS X El Capitan 10.11.6 (6.21 GB) via this link which will open first in the Browser, then in the App Store.
OS X El Capitan
This version of OS X El Capitan is for users running OS X Snow Leopard who would like to upgrade to macOS Sierra. If you are running Snow Leopard and would like to upgrade to Sierra, you need to install El Capitan first. This version of El Capitan can also be installed on Mac computers that are not comparable with Sierra.
Note: If doing this to downgrade from macOS Sierra.
In order to use the Install OS X El Capitan.app from macOS Sierra you need to create a USB Installer and boot the Mac with it. You'll also need to erase the Macintosh HD and perform a clean install. Make sure you have proper User Data Backups from which to restore your Data before erasing the Macintosh HD.
Have a look at Create a bootable installer for OS X. Excerpt show below:
Use the 'createinstallmedia' command in Terminal
- Download the OS X installer from the Mac App Store. Quit the installer if it opens automatically after downloading. The installer will be in your Applications folder.
- Mount your USB flash drive or other volume. You could also use a secondary internal partition.
- Open the Terminal app, which is in the Utilities folder of your Applications folder.
- Use the
createinstallmediacommand in Terminal to create the bootable installer. Examples of this command are in the next section. For detailed usage instructions, make sure that the appropriate Install OS X app is in your Applications folder, then enter one of the following paths in Terminal:Path for El Capitan:
/Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmediaExamples
This is the basic syntax of the command. Replace
volumepathwith the path to your USB flash drive or other volume, and replaceinstallerpathwith the path to the Install OS X app.createinstallmedia --volume volumepath --applicationpath installerpathThe following examples assume that the OS X installer is in your Applications folder and the name of your USB flash drive or other volume is MyVolume:
Example for El Capitan:
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app
Best Answer
If you downloaded the Sierra installer before using your Apple ID, you should be able to download it again using the Purchases tab in the Mac App Store. If the installer does not show up in that list, try downloading it directly from the Mac App Store.
I do want to point out that it’s quite easy to reinstall macOS in case something goes wrong while updating. Just make sure you have a backup (e.g. with Time Machine) and you should be fine. In case something does go wrong, press and hold the power button to force you Mac to shutdown. Turn it on and immediately press and hold cmd + R until you see the Apple logo. You should now be able to reset your Mac from there.