Did an error occur while preparing to install? Easy fixes!


You may receive the error message “An error occurred while preparing to install” while updating your MacBook to the latest version of macOS.

This process is usually straightforward, but you may experience update issues. Many MacBook users have the same problem and get an installation error pop-up message while updating their MacBook.

This error appears when you try to install, reinstall or update your macOS. This guide walks you through several troubleshooting steps that you can try.

How to Fix “An Error Occurred While Preparing to Install” on Mac

If your MacBook says an error occurred while preparing to install, boot into Safe Mode and make sure the date and time settings are correct. Then boot into recovery mode and try to reinstall macOS without erasing the drive. This will fix the problem in most cases and scenarios.

However, the error message may persist after restarting. Don’t worry, we have more fixes for you to try.

1. Change/check date and time

When you want to upgrade or install a new version of macOS, the installer tries to connect to Apple servers. The servers regularly check the date and time of the connection.

Therefore, if your MacBook’s date and time settings are incorrect, the installer displays an error message stating that something unusual happened during the process.

So check the time and date settings before you start upgrading/installing the latest operating system to make sure it’s correct. There are two ways to do this; System Preferences and macOS Recovery.

System Preferences

  1. Open apple menu and select System Preferences.
  2. Go to the Date and hour option.
  3. Enable Set date and time automatically.
  4. Make sure your region is chosen correctly.
  5. Restart your Mac and try installing/upgrading macOS to check if the issue has been resolved or not.

macOS Recovery Mode

  1. Switch off your Mac.
  2. Turn it on and hold down the Command (⌘) + R keys.
  3. Hold the keys until the Apple logo appears on the screen.
  4. Release the keys and your Mac will boot into macOS Recovery Fashion.
  5. Click on Utilities in the menu bar.
  6. Open Terminal in the drop-down menu.
  7. If you have an active internet connection, enter the following command to automatically update the time and date settings.
    ntpdate -u time.apple.com
  8. If you do not have an active Internet connection, enter the following command to manually change the date and time: Date [mm][dd][HH][MM][yyyy]
  9. Note that you must enter the above command (month, day, hour, minutes and finally the year) without any spaces.
    date 0518171215
  10. Quit it Terminal.
  11. Try the installer to see if the problem has been solved or not!

2. Use macOS Recovery

If the above solution didn’t fix “An error occurred while preparing to install” error on your Mac, you can use the built-in macOS Recovery.

The Command (⌘) + R keys will boot your Mac into Recovery Mode, with different key combinations for different versions of macOS.

There is a list of different key combinations and you can choose the one that suits you best. It’s quite simple; follow the steps described below:

  1. Switch off your Mac.
  2. To light up your Mac using one of the following key combinations:
    1. Command (⌘) + R: reinstall the latest version of macOS installed on your Mac.
    2. Option + Command (⌘) + R: update your Mac to the latest compatible version of macOS.
    3. Shift + Option + Command (⌘) + R: install the version that came with your Mac device.
  3. Click on Reinstall macOS to continue the installation process.

3. Re-download the installer

If none of the solutions above worked, there may be a problem with the installer you are using, which may be corrupt or broken.

In this case, you can download the installer again, and usually the problem will be solved. Before downloading the installer, delete the previous one from your Mac. Then continue downloading.

4. Reinstall the operating system without erasing the drive

Sometimes you need to erase the disk before reinstalling the operating system. To do this:

  1. Switch off and on your Mac and press and hold Command (⌘) + R.
  2. Release the keys to boot into safe mode and open the Utility menu.
  3. Select disk utility and click Continue.
  4. Select the disk, which is MacintoshHD for most users.
  5. Click on the FIRST AID option.
  6. Wait a few minutes until the Do the button activates. Click on it.
  7. Go out disk utilitycome back to Utility menuand select Reinstall the operating system.

5. Reinstall the operating system after erasing the drive

If reinstalling the operating system does not work, try erasing the disk first, then continue the process.

  1. To restart your Mac, and hold down Command (⌘) + R.
  2. Select a user whose password you have and enter the administrator password (if requested).
  3. Picking out disk utility and knock Continue.
  4. Select MacintoshHD and click on the Wipe off tongue.
  5. Select the type of format to Mac OS Extended (Journaled) or APFS (as recommended by Disk Utility).
  6. If you see a Erase volume group button, click this button instead of Wipe off.
  7. To leave disk utility and back to the Utility the window.
  8. Select Reinstall macOS.

6. Recreate your Fusion Drive and add a new volume

If your MacBook has a Fusion Drive, use this technique. A Fusion Drive is made up of two separate drives that have been merged together. It is usually a hybrid of a Serial ATA drive (HDD) and an SSD.

To fix “An error occurred while preparing to install” error on your Mac, you’ll need to erase and reformat the disk using Disk Utility and the macOS Extended option ( logged). After that, follow the steps below:

  1. Use the Utility menu and throw Terminal.
  2. Check the Unix names of your drive by running the command below:
    internal diskutil list
  3. It is important to note which is the HDD and which is the SSD. For most users, HDD is Disk 1 and SSD is Disk 0.
  4. Now run the command below to force dismount the logical volume:
    diskutil force unmount disk2s1
  5. Reformat your disks by running the following commands:
    diskutil eraseDisk JHFS+ SSD0
    diskutil eraseDisk JHFS+ HDD disk1
  6. Run the command below to recreate the disk:
    diskutil cs create “Macintosh HD” disk0 disk1
  7. Create a logical volume on the disk with the command below:
    diskutil cs createVolume “Macintosh HD” JHFS+ “Macintosh HD” 100%
  8. Go out Terminal and reinstall macOS.

7. Contact Apple Support

If none of the solutions mentioned above work for you, it might mean that you have a hard drive problem. In this case, you will need to contact Apple Support for assistance.

If your Mac has a hard drive, you need to replace it. Take your MacBook to the nearest Apple Store, and they’ll repair or replace it for you.


To summarize, if your MacBook says an error occurred while preparing to install, here’s what you can do:

  • Click on Utilitiesthen Terminal.
  • If you have an Internet connection, type the following command and press Enter: ntpdate -u time.apple.com. This will automatically update the date and time on your MacBook.
  • If you don’t have an internet connection, enter these commands: date mmddHHMMyyyy.
  • For example, if it is currently 8:25 p.m. on July 17, 2022, the command would look like this: “date 0717082522”. So enter: date 0717202522 in the terminal and press enter.
  • Make sure the time and date are correct, then quit terminal and try reinstalling OS X.

If the error does not go away, you should try erasing the drive and reinstalling macOS. If nothing works, take your MacBook to the Apple Store and let them fix the problem.

Let me know if this helped fix “An error occurred while preparing to install”. If you managed to do anything else, leave a comment below!


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