[Fixed] An Error Occurred While Preparing the Installation on Mac

”Need help with this. "an error occurred while preparing the installation. try running this application again."

- A Question from Reddit.

It should be easy and smooth to install macOS. However, sometimes, things don't go as expected. If you're facing the same "An error occurred while preparing the installation. Try running this application again" issue while installing the macOS you want, don't miss out on this blog post. Here, we will first explain what the message means, and then provide you with some effective steps to address it.

Without further ado, let's get started.

What Does "An Error Occurred While Preparing the Installation" Mean on Mac?

When you see the message “An error occurred while preparing the installation. Try running this application again,” it means that your Mac encountered an issue while trying to install macOS. This error is resulted from various reasons. Below are the common ones:

• Incorrect Date and Time settings.
• Internet connection issues.
• Insufficient storage space on your Mac.
• Corrupted installation files.
• Problems with Apple's servers.
• Hardware issues.

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

Now that you understand the causes behind this frustrating issue, follow the methods given below to fix it.

1. Check the Date and Time Settings

Incorrect Date and Time settings are the most common reason for "An error occurred while preparing the installation". To fix this, first check if the Date and Time settings are correct. If not, correct them.

1. Click the Apple menu and select System Settings.
2. Click General > Date & Time.
3. Check if the Date and time is correctly set up.
4. Make sure "Set time zone automatically using your current location" is enabled.

Related Article: How to Change Time Zone on Mac - 2 Easy Ways

2. Repair Your Disk in macOS Recovery Mode

If there's an issue with your Mac hard drive, it might prevent your Mac from installing macOS. To troubleshoot, use the macOS's built-in tool, Disk Utility, to repair your disk.

Here are the steps:

1. Click the Apple menu > Shut down to turn off your Mac.
2. Restart your Mac in Recovery Mode.
3. In the macOS Utilities or macOS Recovery window, select "Disk Utility", then click the "Continue" button.
4. In Disk Utility's sidebar, select your startup disk (usually named "Macintosh HD").
5. Click the "First Aid" button in the toolbar and then click "Run" to check and repair your disk.
6. Once the process is complete, try the installation again to see if the problem is resolved.

If this method doesn’t work, return to the macOS Recovery screen and select "Reinstall macOS" to reinstall the version of macOS that originally shipped with your Mac or the closest compatible version. However, if you have upgraded your Mac, the recovery partition may have been updated to reflect the version you upgraded to. In this case, the reinstalled macOS is most likely the version currently installed on your Mac.

3. Re-download the macOS Installer

The error “An error occurred while preparing the installation. Try running this application again" might also result from the corrupted macOS installer. In such a case, re-download the installer with the App Store.

To ensure you’re downloading the full installer rather than a combo update, click the download link below:

• macOS Sonoma (12.12 GB)
• macOS Ventura (12.12 GB)
• macOS Monterey (12.13 GB)
• macOS Big Sur (12.58 GB)
• macOS Catalina (4.9 GB)

Once you find the macOS you want in the App Store, click the blue "Get" button to download it. See what to do if the requested version of macOS is not available.

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4. Install macOS in Safe Mode

When your Mac boots in Safe Mode, only the essential system components and services are launched. Therefore, to avoid software conflicts that may cause macOS installation errors, try installing macOS in Safe Mode.

Here's how to start your Mac in Safe Mode:

• If your Mac is with Apple Silicon:

  1. Shut down your Mac.
  2. Press and hold the power button until the Startup Options window appears.
  3. Select your volume.
  4. While holding down the Shift key, click Continue in safe mode.
  5. Your Mac will automatically restart.

• If your Mac is Intel-based:

  1. Start your Mac and keep the Shift key held down.
  2. Release the key when the login window appears.
  3. Log in to your Mac.
  4. You will see Safe Mode in the menu bar.

5. Try Internet Recovery Mode

Internet Recovery Mode is a feature introduced on Macs released after mid-2011. It allows you to reinstall macOS even if your computer’s startup disk is damaged or has been completely erased. If the standard Recovery Mode doesn’t work, try using Internet Recovery Mode to reinstall macOS.

Here's how:

1. Restart your Mac and hold down Option + Command + R to enter Internet Recovery Mode. (If you're using a M-series Mac, press and hold the power button to load more startup options. On the startup options screen, press and hold Option + Command + R for a few seconds to enter Internet Recovery Mode.)
2. Connect to a Wi-Fi network if prompted.
3. When you see the macOS Utilities window, choose "Reinstall macOS" and follow the on-screen instructions.

6. Install macOS with a Bootable USB Installer

Another method is to install macOS using a bootable USB installer. To create one, you'll need a USB flash drive with at least 16 GB of storage. First, format the drive using Disk Utility. Next, download the full macOS installer you want, either from the App Store or from other sources. Finally, use Terminal to create a bootable USB installer for macOS.

For more detailed steps, check out How to Create a Bootable USB for macOS Sonoma/Ventura/Monterey.

Once the bootable USB macOS installer is ready, connect it to your Mac, start your Mac in Startup Manager, select the inserted USB flash drive, and press Return to start your Mac from the bootable USB.

Related Article: [Full Guide] How to Boot Your Mac from a USB Drive

The Bottom Line

Reading so far, you should already know what the error message "An error occurred while preparing the installation" means and how to fix it in 6 steps. Hopefully, at least one of the above methods will solve your problem.

If you have a better solution, please let us know via email or social media. We would greatly appreciate your input.