An Error Occurred While Preparing the Installation? Easy Fixes!

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You may get the “An Error Occurred While Preparing the Installation” error message while updating your MacBook to the latest macOS version.

This process is usually straightforward, but you may encounter update problems. Many MacBook users have the same issue and get a popup installation error 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 you can try.

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

If your MacBook says that an error occurred while preparing the installation, boot into Safe Mode and make sure the date and time settings are correct. Next, boot into Recovery Mode, and try to reinstall the macOS without erasing the drive. This will solve the problem in most cases and scenarios.

However, the error message may remain after the reboot. Don’t worry, we’ve got 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 the Apple servers. Servers routinely check the date and time of the connection.

As a result, if your MacBook date and time settings are incorrect, the installer shows an error message indicating something unusual happened during the process.

So, check the time and date settings before starting the upgrade/installing the newest OS to ensure it is 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 & Time option. 
  3. Enable Set date and time automatically.
  4. Make sure your region is correctly chosen. 
  5. Restart your Mac and try installing/upgrading the macOS to check if the problem has been solved or not.

macOS Recovery Mode

  1. Power off your Mac.
  2. Turn it on and press and hold 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 Mode
  5. Click on Utilities on the menu bar. 
  6. Open Terminal from the drop-down menu. 
  7. If you have an active internet connection, enter the following command to update the time and date settings automatically. 
    ntpdate -u time.apple.com
  8. If you don’t have an active internet connection, type 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. Exit the 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 the “An Error Occurred While Preparing the Installation” error on your Mac, you can use the built-in macOS Recovery.

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

There is a list of various combination keys, and you can pick the one that works best for you. It is pretty simple; follow the steps outlined below:

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

3. Re-Download the Installer

If none of the above solutions worked, there might be a problem with the installer you are using, which can be corrupted 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 with the download. 

4. Reinstall the OS Without Erasing the Drive

Sometimes, you must erase the drive before reinstalling the OS. To do this:

  1. Turn 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 Macintosh HD for most users.
  5. Click on the First Aid option.
  6. Wait for a couple of minutes until the Done button activates. Click on it. 
  7. Exit Disk Utility, go back to Utility Menu, and select Reinstall OS.

5. Reinstall the OS After Erasing the Drive

If reinstalling the OS won’t work, try erasing the drive first and then continue the process. 

  1. Restart your Mac, and press and hold Command (⌘) + R.
  2. Select a user you have the password for and enter the administrator password (if asked).
  3. Choose Disk Utility and hit Continue. 
  4. Select Macintosh HD and click on the Erase tab. 
  5. Select the format type to Mac OS Extended (Journaled) or APFS (as recommended by Disk Utility).
  6. If you see an Erase Volume Group button, click that button instead of Erase
  7. Quit Disk Utility and return to the Utility window.
  8. Select Reinastall 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 fused. This is typically a hybrid of a Serial ATA drive (HDD) and an SSD.

To fix the “An Error Occurred While Preparing the Installation” error on your Mac, you’ll need to erase and reformat the disk using the Disk Utility and the macOS Extended (Journaled) option. After that, follow the steps below:

  1. Use the Utility menu and launch Terminal.
  2. Check your drive Unix names by running the command below:
    diskutil list internal 
  3. It’s important to note which one is the HDD and which one is the SSD. For most users, the HDD is disk 1, and the SSD is disk0.
  4. Now, run the command below to force-unmount the logical volume:
    diskutil unmount force disk2s1 
  5. Reformat your drives by running the following commands:
    diskutil eraseDisk JHFS+ SSD disk0
    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. Exit Terminal and reinstall macOS.

7. Contact Apple Support

If none of the abovementioned solutions worked for you, it could mean that you have a hard disk issue. In that case, you’ll need to contact Apple Support for help.

If your Mac has an HDD, you must replace it. Take your MacBook to the nearest Apple Store, and they will repair or replace it for you. 

Conclusion

To summarize, if your MacBook says that an error occurred while preparing the installation, here is what you can do:

  • Click on Utilities, then Terminal.
  • If you have an internet connection, enter the following command and hit enter: ntpdate -u time.apple.com. This will automatically update the date and time on your MacBook.
  • If you have no Internet connection, then enter these commands: date mmddHHMMyyyy.
  • For example, if it’s currently 8:25 pm, July 17, 2022, the command would look something like this: “date 0717082522”. So enter: date 0717202522 into the terminal and hit enter.
  • Make sure that the time and date are correct, then exit the terminal and try to reinstall the OS X.

If the error doesn’t disappear, you should try erasing the drive and reinstalling the macOS. If nothing worked, take your MacBook to Apple Store and let them fix the problem. 

Let me know if this helped fix “An Error Occurred While Preparing the Installation”. If you found success doing something else, leave a comment down below!

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As a technophile, Farhad has spent the last decade getting hands-on experience with a variety of electronic devices, including smartphones, laptops, accessories, wearables, printers, and so on. When he isn't writing, you can bet he's devouring information on new technologies making their way to market. He oversees coverage of iPhone, iOS, and Apple Watch for Gotechtor.

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