Common macOS installation error messages and how to fix them

Sometimes, when trying to update your Mac to a newer macOS version, you can encounter error messages saying that “macOS could not be installed on your computer,” “An error occurred while preparing the installation,” “Your Mac does not have enough storage,” or the like. Fortunately, you can do lots of things to fix these errors, so let’s get started.

Before we dive into detailed steps, let us show you the most common error messages and the quickest ways to fix them.

Common macOS installation error messages and how to fix them

Below, you’ll find a few examples of installation error messages encountered on the latest macOS version, meaning that depending on the operating system you are trying to install, the wording of the message may be slightly different.

Core/general installation errors

• “macOS could not be installed on your computer.”
• “The macOS installation couldn’t be completed.”
• “Installation of macOS could not continue.”
• “An error occurred while installing the update.”

Best fixes: Verify Mac compatibility, free up space, check time and date, check Apple System Status, ensure a stable internet connection, run First Aid

Verification, damaged installer, and personalization errors

• “This copy of the Install macOS [version] application is damaged, and can’t be used to install macOS.”
• “The macOS installer is damaged.”
• “Unable to verify macOS.”
• “Failed to personalize the installer.”

Best fixes: Ensure a stable connection, check time and date, re-download the installer, temporarily disable VPN and security software, check Apple’s servers, free up disk space, update in safe mode

Download and network-related errors

• “An error occurred while downloading macOS.”/“An error occurred while preparing the installation.”
• “The recovery server could not be contacted.”
• “Installation requires downloading important content. That content can't be downloaded at this time. Try again later.”
• “The requested version of macOS is not available.”

Best fixes: Verify Mac compatibility, ensure a stable connection, check time and date, re-download the installer, check Apple’s servers, free up disk space

Storage/disk errors

• “There is not enough free space on the disk to install macOS.”
• “Your Mac does not have enough storage space.”
• “The target volume does not have enough free space.”
• “macOS cannot be installed on this disk.”

Best fixes: Free up space, run First Aid

Compatibility errors

• “macOS [version] cannot be installed on this computer.”/“macOS [version] cannot be installed on Macintosh HD.”
• “This version of macOS cannot be installed on this computer.”
• “macOS is not compatible with this Mac.”

Best fixes: Do not upgrade your Mac or try installing macOS on an unsupported Mac (the latter works for macOS Tahoe or older, but it is generally not recommended because it can affect the stability and performance of your device.

Recovery-specific errors

• “The recovery server could not be contacted.”
• “The installer information on the recovery server is damaged.”
• “An error occurred while preparing the installation.”
• “The recovery system is not available.”

Best fixes: Re-download the installer, run First Aid, reset NVRAM and SMC (Intel-based Macs only), check Apple’s servers, temporarily disable VPN and security software

Post-installation/startup symptoms

• Mac stuck on the Apple logo/progress bar after installation.
• Mac repeatedly returns to the installer.
• Flashing folder with a question mark.
• Mac starts into Recovery after installation.
• Mac won't boot after macOS installation.

Best fixes: Reset NVRAM and SMC (Intel-based Macs only), force restart your Mac (press and hold the power button until your Mac shuts down), run First Aid, reinstall macOS, update in safe mode

Why does “macOS could not be installed on your computer” or another error appear?

There are several reasons why you might see installation-related error messages. Here are some of the most common:

• Your Mac doesn’t support the version of macOS you’re trying to install.
• There was a problem downloading the installer.
• You don’t have enough space to install a new version of macOS.
• There’s a problem with the disk on your Mac.
• A piece of software like a launch agent or launch daemon is interfering with the upgrade.

How to fix “macOS could not be installed on your computer” and other errors

Now that you know which error messages you may encounter, why they occur, and which fix to try first, let us dive into detailed solutions.

But before trying to fix anything, restart your MacBook and make sure that your internet connection is stable. Also, temporarily disable your VPN (System Settings > VPN) and security software (including antivirus apps) — they may interrupt the download and installation of macOS.

Also, go to the Apple System Status page and check if there are no update-related outages (the dot next to macOS Software Update should be green). If the dot is yellow/red, just wait it out and try again later.

1. Check if your Mac is compatible

It is the very first thing to try. The best way to do that is to open the App Store app, search for the macOS version you’re trying to install, and scroll down the Compatibility section. You should see a message that says, “works on this Mac.” Alternatively, go to Apple’s website support pages and search for the minimum system requirements. You might need to reboot into safe mode (see below) to check because if you do a normal restart, your Mac may immediately relaunch the installer.

Note: If you need to check compatibility for macOS Tahoe and Golden Gate, go to Apple Support — these installers can no longer be downloaded via the App Store. The upgrade is possible only via System Settings.

2. Set the correct date and time

Sometimes, the error may occur if the date and time settings are misconfigured. Therefore, it is recommended to set the correct ones. You can do it from System Settings:

1. Go to System Settings > General. 
2. Click Date & Time.
3. Check the date and time and make changes if needed. It is better, though, to turn on the option that allows to set time and date automatically.

3. Re-download the installer file

It may be that you encountered the error because the installer is corrupted. To try and fix it, go to the Downloads folder, find the macOS installer, and delete it. Now, go to the App Store and type the name of the macOS version you’re trying to install in the search bar. Click Get to download it and try to install it once again.

If you want to download Tahoe or Golden Gate, you will need to run this command in Terminal:

softwareupdate --fetch-full-installer --full-installer-version [number]

Example: softwareupdate --fetch-full-installer --full-installer-version 26.6.2 to download macOS Tahoe 26.6.2

Check out this page for more detail.

4. Free up space

You’ll need up to 25GB of free space on your main drive to download and install an update to macOS. If you don’t have that much free space, it’s time to clear out the junk and free up space. The quickest and easiest way to do that is to use a popular app — CleanMyMac by MacPaw. It will free up tons of space, neutralize malware, and update your apps in one single scan.

Start your free CleanMyMac trial, install, and then open it. 

1. Open the app and click Scan.
2. When it’s finished, click Run to remove junk files or click Review to see what it has found.

5. Try to update macOS in safe mode

First, boot into safe mode. It disables startup items, launch agents, and everything else except the bare minimum macOS needs to function. Steps differ for different Mac models.

To start up your Intel-based Mac in safe mode:

1. Shut down your Mac and wait 10 seconds.
2. Restart your Mac and press the Shift key.
3. Release the Shift key after the login window shows up.
   

To start up your Mac with Apple silicon in safe mode:

1. Shut down your Mac and wait 10 seconds.
2. Press and hold the power button until the startup options window shows up.
3. Select a startup disk.
4. Press the Shift key and click Continue in Safe Mode.
   
5. Release the Shift key.

If the problem was that background items were interfering with the upgrade, safe mode would fix that. If it works, you should restart your Mac normally after the installation and remove any background agents you don’t need. But you can try to install an update directly from safe mode.

The simplest way to remove background agents is to use CleanMyMac. Here’s how:

• Download, install, and open CleanMyMac (get a free trial).
• Choose Performance from the sidebar.
• Run a scan.
• Review your background items and disable any you don’t need.

6. Reset the NVRAM and SMC

The NVRAM on your Mac stores data even after your Mac shuts down or restarts, unlike regular RAM, which is flushed every time you restart. NVRAM persists, thanks to a small amount of power supplied by your Mac’s internal battery. Resetting NVRAM rarely has any effect, but it can do in some situations, and as it won’t do any harm, it’s worth trying. It’s quite tricky to do, so you might need some help.

Restart your Intel-based Mac while holding the Command + Option (Alt) + P + R keys and wait until you hear a startup chime. It may take a little longer than normal to restart twice, but the NVRAM will have reset once it’s done.

Apple state that there are no instructions for resetting NVRAM on Apple silicon. However, some forum users claim that turning off a Mac and turning it on again after 30 seconds helps. 

Next up, reset SMC. It is responsible for hardware-related settings, but sometimes helps with installation glitches. Like with NVRAM, if you have a Mac with Apple silicon, there are no official instructions for the reset, but you can try restarting your device.

For an Intel-based Mac, follow these steps:

1. Shut down your Mac.
2. Press Shift+Control+Option on the left side of your keyboard and press the power button at the same time.
3. Hold these keys for 10 seconds.
4. Release the keys.
5. Press the power button again to turn on your Mac.

For other Mac models, check out this guide on how to reset SMC and NVRAM. It includes steps for MacBooks with a T2 security chip, those with a removable battery, iMac, and other Mac computers.

7. Go to recovery mode

Another solution is to boot into recovery mode and reinstall macOS. Like with safe mode, steps are different for different Macs.

For an Intel-based Mac:

1. Go to Apple menu > Restart.
2. Immediately press and hold Command+R.
3. Don’t release the keys until you hear Mac’s startup sound or until the Apple logo appears.

For a Mac with Apple silicon:

1. When turning on your Mac, press and hold the Power button.
2. Keep it pressed until you see startup options.
3. Click the Gears icon (Options) and hit Continue.
4. You may be asked to select a user and enter their administrator password. Follow the on-screen instructions and click Next after any action you take.

When you see the macOS Utilities window, you have two choices. You can either restore your Mac from a Time Machine backup if you have one or reinstall macOS. Choose the option that works better for you and follow the on-screen instructions to proceed. 

8. Run First Aid

If nothing else helped, it may be that the error is caused by corrupt disk permissions and issues with fragmentation. Luckily, this one is an easy fix because macOS comes with a built-in tool designed for the purpose. Here’s how to do it: 

1. Go to your Applications folder and click Utilities. 
2. Double-click Disk Utility to open it. 
3. Select Macintosh HD from the sidebar. 
4. Click First Aid > Run.

If it does not work, boot your Mac into recovery mode as described above and run First Aid again.

There are a number of things you can do to fix your Mac when you see the message “macOS could not be installed on your computer.” If the problem is that you don’t have enough space, you can use CleanMyMac to get rid of files you don’t need. Otherwise, go through the above steps one at a time until you’re able to install a new version or update to macOS. If none of the tips worked, consider erasing your Mac and clean installing macOS as a final resort — learn more in our ultimate macOS reinstall guide.