How to Fix 'An Error Occurred While Preparing the Installation' Error [macOS Upgrade Issue]

Dany updated on Oct 10, 2024 to Computer Instruction | How-to Articles

If you receive an error message saying 'An Error Occurred While Preparing the Installation', follow this guide to fix the issue and reinstall macOS. This straightforward guide will show how to fix an error while preparing the installation. Once done, you will be able to get back the access. However, it's essential to check and recover lost data in case of an issue or even when you have fixed it.

Workable Solutions Step-by-step Troubleshooting
1. Restart Mac Fix An Error Occurred While Preparing the Installation Restarting the system is one of the simplest ways to resolve the 'An Error Occurred While...Full steps
2. Stay in a Stable Internet Environment to Fix the Issue You might not know, but the installer requires the internet to complete the process. With the net...Full steps
3. Check the Time and Data on Your Mac Click on the Apple Menu and select System Settings from the drop-down menu. From the left-hand...Full steps
4. Try to Install macOS in Mac Safe Mode Turn off the system and start it again. Now, press and hold the Shift key till you come across...Full steps
Other Solutions Did you know you can fix the installation error using a combo update? You can update the system with...Full steps

An Error Occurred While Preparing the Installation Overview

One of the most common errors you can encounter while installing a macOS base system is the "An Error Occurred While Preparing the Installation".The error mainly occurs due to installer issues and needs to be resolved immediately.

The reasons that can lead to the "An Error Occurred While Preparing the Installation" are:

  • Corrupted installer
  • Incorrect time and date details on the system

However, there are several solutions you can apply to fix this issue. Read on the section below to know more!

If you are not familiar with manually creating a macOS installer with a USB, you should try a tool for help. EaseUS Data Recovery Wizard for Mac helps create a bootable macOS installer quickly and safely. It is a free feature; download it now!

Back Up Your Mac and Never Lose Data

Back up and restore your MacBook/iMac without Time Machine, iCloud, or external hard drives.

✨Step 1. Connect USB Flash Drive and Choose a macOS Version

Launch EaseUS recovery software, and choose "macOS Installer" from the Advanced Features. Insert a USB that has more than 16GB of free storage space.

  • Option 1: Choose a macOS version you want to install, and a new windows will ask you to download macOS installer from App Store. After downloading the installer, click "Refresh".
  • Option 2: If you have already downloaded macOS installer, choose "Add" and select the installer you have downloaded.

Finally, you can choose "Create macOS Installer" to start creating the bootable installer. You can select various macOS versions like macOS Sequoia, Sonoma, Ventura, Monterey, Big Sur, and older versions.

✨Step 2. Erase the USB and Create a macOS Installer

A notice window will appear to warn you this operation will remove everything on this USB. Make sure you have backed up data and nothing important is left on this USB, click the "Erase and create".

✨Step 3. Wait and Check How to Use macOS Installer

The software will automatically format the USB and download macOS installer files. After creating the bootable macOS installer, click the blue link on the interface to learn how to use the macOS Installer boot device to install macOS. Finally, click "Finish" to complete the whole process.

Method 1. Restart Mac to Fix 'An Error Occurred While Preparing the Installation'

Restarting the system is one of the simplest ways to resolve the 'An Error Occurred While Preparing the Installation' error. For that, press the power button, and wait for the system to shut down. Wait a moment and press the power button again to turn on the system. Or you can restart MacBook Pro or Mac with the macOS Restart option.

Method 2. Stay in a Stable Internet Environment

You might not know, but the installer requires the internet to complete the process. With the net, you can get firmware and related information that is particular to your system, and that is why you need to have a stable internet environment.

Method 3. Check the Time and Data on Your Mac

Correct time and data details are crucial for resolving the "An Error Occurred While Preparing the Installation" error. For that, take a look at the steps you need to follow:

Step 1. Click on the Apple Menu and select System Settings from the drop-down menu.

Step 2. From the left-hand bar, select General and click on Date and Time from the right-hand.

Step 3. Go ahead with the "Set date and time automatically" option.

Step 4. Opt for the region you are in from the drop-down menu.

Method 4. Try to Install macOS in Mac Safe Mode

Mac Safe Mode is one of the most advanced properties of Apple tech. With this mode, only the vital components of the system are run. In that case, third-party apps are unavailable, eliminating any chance of contributing to that error.

Here are the steps you need to adopt:

Step 1. Turn off the system and start it again.

Step 2. Now, press and hold the Shift key till you come across the Apple logo. Log in.

Step 3. Your system will enter Safe Mode. Now, you can install macOS Monterey or other versions.

Note: Click the link to learn more if you can't install macOS Ventura.

Method 5. Use a macOS Combo Update to Fix the Installation Error

Did you know you can fix the installation error using a combo update? With this combo update, you can update the system with the major release within the previous macOS version. These combo updates are available on the official website of Apple. Remember that these files are huge and need a stable and fast internet connection.

Method 6. Reinstall macOS in Mac Recovery Mode

You can also use the Mac Recovery Mode to resolve the installation error. Check out the steps:

Step 1. Turn off the system. Turn it on and press Option-⌘-R keys/Shift-Option-⌘-R/Command (⌘)-R immediately.

Step 2. Now, select Reinstall macOS. Click on Continue.

Note: Shift-Option-⌘-R combination keys are used when you want the original macOS version. Option-⌘-R keys combination is used to get the latest compatible Mac version. You can reinstall the previous macOS with Command (⌘)-R keys.

Method 7. Factory Reset Mac and Reinstall macOS

You can also try to factory reset Mac without password in the Recovery Mode and reinstall the OS to see if the issue is resolved. Or you can erase all content and settings on your Mac to factory reset it. For that, you must follow these steps:

Step 1. Use Erase Assistant to erase the system. (Only macOS Monterey and later versions can use this option.)

Step 2. Follow the prompt to erase your Mac step by step. Now, click "Continue".

Step 3. Select Options. Proceed with Continue. Follow the instructions given on the screen.

Step 4. Opt for Reinstall for your macOS release from the Recovery app window. Select Continue. Follow the instructions given.

Note: The steps may vary based on the Mac model you have.

Method 8. Contact Apple Support

You can always rely on the Apple support team if nothing else works. Visit the Apple Support store nearby to resolve the issue immediately.

Restore Lost Data After Fixing 'An Error Occurred While Preparing the Installation'

Have you lost data while trying to fix the "An Error Occurred While Preparing The Installation" problem? In that case, don't panic! Instead, install the best data recovery software - EaseUS Data Recovery Wizard for Mac. Irrespective of the cause of data loss, you can quickly restore it.

Here are some highlights of this recovery program:

  • EaseUS Mac recovery program is an efficient and user-friendly software explicitly made to aid data retrieval. Eves a new Mac user can operate it without any difficulties.
  • Mac users can quickly recover deleted files Mac from various data types, such as emails, documents, photos, and videos.
  • You can also get back data from different Mac-based devices like memory cards, fusion drives, HDDs, etc. Also, it supports SSD Trim data recovery.

Here are the easy-to-implement steps you need to follow to use this tool:

Step 1. Search for lost files

Select the disk location to search for lost files (it can be an internal HDD/SSD or a removable storage device) on macOS Sierra, High Sierra, Mojave, Catalina, Big Sur, Monterey, Ventura, and the latest Sonoma. Click the "Search for lost files" button.

Step 2. Go through the scanning results

EaseUS Data Recovery Wizard for Mac will immediately scan your selected disk volume and display the scanning results.

Step 3. Select the file(s) and recover

In the scan results, select the file(s) to preview and click the "Recover" button to have them back.

Bottom Line

The "An Error Occurred While Preparing the Installation" is a common error most Mac users often encounter. Luckily, there are various solutions one can adopt. For instance, you can reinstall the macOS via Recovery Mode or choose the combo update.

Regardless of the precaution you adopt, data loss is a possibility. In that case, you must choose a professional data recovery tool. Install EaseUS Data Recovery Wizard for Mac and take advantage of the beneficial features.

Try this exciting data recovery software today!

An Error Occurred While Preparing the Installation FAQs

These are the solutions you can try to fix the "An Error Occurred While Preparing the Installation". But, to know more, take a look at the questions and answers listed below -

1. How to Fix the macOS Ventura installation failed?

To fix the macOS Ventura installation failed problem, you can check if you have storage space. Besides, you also need to assess the Firewall settings, restart the system, and see if the issue is resolved.

2. Why the 'An Error Occurred While Preparing the Installation' error appear on my Mac?

The "An Error Occurred While Preparing the Installation" error appears on your Mac for different reasons. These include corrupt installers and the inaccurate date and time information.

3. How to fix the 'An Error Occurred While Preparing the Installation' error?

Different ways exist to resolve the 'An Error Occurred While Preparing the Installation' error. For instance, you can install macOS in Mac safe mode. You can also check the time and date and use the combo update.

4. How to recover data after reinstalling macOS to fix 'An Error Occurred While Preparing the Installation'?

To recover data after reinstalling macOS to fix 'An Error Occurred While Preparing The Installation', opt for a data recovery tool. You can choose EaseUS Data Recovery Wizard for Mac!