Cannot install macOS Monterey: Try Solution on Your Mac

Last Updated on Nov 9, 2021

Apple just ready to launch macOS Monterey Public macOS in fall 2021 after successfully announced the first macOS Monterey Beta [macOS 12] in WWDC 2021, and as like each year, Apple released Developer Beta testing of the next major software update of its devices (iPhone, iPad, Apple Watch, Mac’s, and Apple Tv) with Big Updates and Improvements. The Public version will be available in the upcoming fall of 2021, but before users want to touch the latest features on its device, they can enroll their device for the beta program to download and install if they wish to remove macOS Monterey Beta to Get Public macOS when its release.

we are happy to help you, submit this Form, if your solution is not covered in this article.

I have Mac, iPhone, and Apple Watch. I try to install macOS 12 on my MacBook Pro as an app developer, but unfortunately, macOS Monterey won’t install. So I tried bottom troubleshooting to fix the issue. If you have the Same symptoms, follow the bottom steps that I have been attempting on my MBP13 2020 and my wife’s M1 MacBook Air and M1 Mac Mini.

After the installer File is downloaded (the entire 12.2G file gets downloaded and then nothing happens; the installation doesn’t start.), installation starts, and when the progress bar reaches 12 minutes, installation interrupts with an error message “An error occurred installing macOS 12. You can try again to complete the installation”.

macOS Monterey Install Problems Reported:

Cannot upgrade to Monterey with non-apple SSD

Cannot upgrade to Monterey with non-apple SSD

Can’t install macOS Monterey beta on M1 external drive
> I tried to download the macOS 12 and install it to an external SSD drive connected to the Apple M1 chip Mac Mini. The installation continues until restart. The external SSD drive cannot be used to boot up.
SSD is erased and set to:
2. GUID Partition Map
This strategy has been used in the last few years with Intel MacBook. I wonder if this is a problem with the macOS or M1 machine?

Same here, getting: “An error occurred while setting “MacOS 12” as the startup disk: The operation couldn’t be completed. (SDErrorDomain error 108.)” when trying to boot to an external drive on M1

macOS Monterey Update not Found


if macOS 12 Monterey Update is not found on your Mac app Store, Or the requested version of macOS is not available 2021 because your Mac is not Supported MacOS Monterey, Or your Mac is running on Monterey Beta Version or MacOS Monterey Developer Beta version – in this case, you have to Remove Monterey Beta from Mac and Wait for new Update Version that’s equal to Monterey public MacOS or Find Monterey on Mac App Store, Otherwise do a clean macOS install on Supported Mac.


Also, Check MacOS Monterey Supported Mac. Let’s following article will help you.

Steps to Fix Cannot install macOS Monterey: 2021 MacOS

Fix 1: Delete installer File and Re-download macOS 12

On your New Software Update install request, your Mac download macOS Monterey installation file in the Applications folder in finder, see the below screen, But if you can’t install or Start Update your Mac, there are too many reasons, your Mac downloaded Buggy file, the Downloaded file is old. I recommend to Delete this File and Re-Download New macOS Monterey file to Mac and install it on your Mac.


Go to the Apple Logo from the top Mac menu > System Preferences > Software Update >


Download and install. hope your problem will be fixed. But still can’t install then follow the other solutions as well.

Software Update Beta to Public macOS install on Mac
Software Update Beta to Public macOS install on Mac

– Then check if it can work for you.

OR try to re-enlisted in the beta program.

Apple System Status

Apple Server & System Status truely depends on your Mac activity like Upgrading macOS Version after Download Latest MacOS Software on Mac.

So, Whenever you Got some annoying error while downloading macOS Software update or Installing MacO, Must check apple system status on your Browser. Find Apple System Status in Other countries.

Fix 2: Reset PRAM/ NVRAM and SMC [For intel Mac only]

  • For M1 Mac: Just Restart your mac, Don’t need to Reset any RAM Memory.
  • Have you an intel Mac or MacBook, then you should go with the Reset PRAM/ NVRAM Process to clean up and re-build all startup Programme value on Mac.

Fix 3: Reboot Your Mac

If you are stuck during the installation then I recommend restarting your Mac and Check for the installation process on your Mac. also During the installation, we need a stable internet connection this also fixes automatically after restart your Mac system.

  • Go to the Apple logo from the top Mac menu > Restart.

Fix 4: Use Personal WiFi & Internet connection

Most of the public WiFi keeps active firewall connections that prevent you from update your Device from the Apple server.

if you are getting the same issue on your own WiFi then change or Try to Update with a Personal hotspot [if you afford it]. Otherwise, I highly recommend using WiFi because 12GBs of Setup need high-speed data transfer.

Fix 5: Turn Off turn of FileVault or Firewall/VPN

here’s the complete guide on how to Manage & Turn off VPN on Mac. Follow the steps below to turn off Firewall and Start the macOS installation quickly.

Also, Disable the antivirus if installed.

  1. Click on the Apple logo from the Mac menu.
  2. Next, Click on System Preferences option > Security & Privacy.
  3. Unlock the window and click on Turn off Firewall.

if the Firewall is already turned off, then skip this and move to the next solution.

Fix 6: Install macOS 12 via App Store.

After I tried (and failed) to install it from App Store, I found that I have a new Application:
/Applications/Install macOS 12


I right-clicked that, clicked “Show Package Contents,” and navigated to Contents -> MacOS, and I double-clicked InstallAssistant.

  • Open the app store on Mac, and Search MacOS with a name to Download Setup file from Mac app store. Click on macOS Version and Get.
Download MacOS monterey setup or DMG file on Mac
Download MacOS Monterey setup or DMG file on Mac

I was able to install it from there.

Fix 7: Free Up Storage on Mac

Insufficient storage for download a new copy of macOS to Your Mac’s Drive and installation required some more free space to extract the setup file and install it on Mac quickly and easily.

So, I recommend keeping release 20 to 30 Gigabytes of Free space on your Mac. We can quickly check and manage from your Mac. Follow the below steps,

  1. Go to the Apple Logo from the top mac menu > About This Mac.
  2. Open Storage Tab > Click on storage-tab-on-mac > Follow the Recommendations and Delete Large unused app from Applications, Media files from Documents.
  3. Now, Go back to Apple Logo > System Preferences > Software Update > Download and install Available software update.

If still, you are getting the error related to Storage then Restart your Mac and try again.

Fix 8: Reinstall install macOS In Recovery Mode

Reinstall macOS On mac is time-consuming but that’s effective if you are following the step in the sequence. First Take Mac Backup in Time Machine, Put your Mac [Intel or M1] in Recovery mode and Reinstall macOS. This reinstallation process will care & fix all the software bug and get installed latest supported macOS Version to Mac without Erase any data and settings.

First Know, is your Mac has intel chip or M1? then follow the below steps,

For M1 Mac,

  1. Shut down your Mac and Wait for 20 seconds.
  2. Now, Press and Hold the Power button [Touch ID button], until you see the Startup Volume and Options screen.options-in-recovery-mode-on-m1-mac
  3. Click on Options > see the Reinstall macOS option > Continue.Reinstall MacOS
  4. Now, Select the Primary Partition if any, And follow the on screen instructions.
  5. That’s it.

For Intel Mac,

  1. Shut Down your Mac and Wait for 20 seconds.
  2. Next, Turn on your Mac and quickly, Press and Hold on the Shift Key, Until your Mac show MacOS utilities Window screen > Reinstall MacOS.macos catalina reinstall on mac
  3. Complete the steps given on screen.
  4. That’s it.

Fix 9: Download Failed Popup Message Error

download-failed-error on Mac

Download failed: An error occurred while downloading the selected updates. Please check your internet connection and try again.

Your Mac with a T2 Security Chip, Allow users to Provide Three layer of security. So Turn on Full Security in Recovery mode. Follow the below steps and Turn on.

  1. Turn on your Mac, Immediately Press and Hold Command + R key from keyboard after Startup apple logo appear on screen. Until you see the MacOS Utilities window on screen.
  2. From top Mac Menu bar, Choose Utilities > Startup Security Utility.
  3. Your Mac will ask to enter your Mac login password for authonticate. login it and Apply the changes.startup-security-utility-on-mac-for-secure-boot
  4. That’s it.

Now, Go back and check the issue is fixed.

Note: Apple Rolled out some Updates on 5th Nov, that Brick MacBook with T2 Security Chip after installing macOS Monterey, So, Keep your MacBook Updated. for Below Models

  • iMac (Retina 5K, 27-inch, 2020)
  • ‌iMac‌ Pro
  • Mac Pro (2019)
  • ‌Mac Pro‌ (Rack, 2019)
  • Mac mini (2018)
  • MacBook Air (Retina, 13-inch, 2020)
  • ‌MacBook Air‌ (Retina, 13-inch, 2019)
  • ‌MacBook Air‌ (Retina, 13-inch, 2018)
  • MacBook Pro (13-inch, 2020, Two Thunderbolt 3 ports)
  • MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports)
  • MacBook Pro (16-inch, 2019)
  • MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports)
  • MacBook Pro (15-inch, 2019)
  • MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports)
  • MacBook Pro (15-inch, 2018)
  • MacBook Pro (13-inch, 2018, Four Thunderbolt 3 ports)

Fix 9: Check Internet Connection

A good Internet connection never disappoints you while installation of a software update. Because you get a quick response from the apple server, Downloading a Large setup file will complete too fast. you can check Internet speed on on any device. I recommend testing on the installation device, here’s your Mac.

Is your internet slow?

  1. Restart your Router
  2. Restart your Mac
  3. Switch to Another WiFi – check you have connected your own wifi Because some public wifi connecting automatically.

Fix 10: Safe Mode on Mac

Safe mode on Mac determines the software issue on startup your Mac in safe mode. And Fix it automatically. so you can complete the macOS software updates without any Download and installation errors.

The safe mode Process is different for M1 Mac and Intel Mac users.

Fix 11: Boot from External Bootable Disk

Note: You must keep a backup of your Mac data in Time Machine [External Drive], Here’s a complete guide to Take Mac Backup in Time Machine.

Make a USB bootable drive for macOS Monterey and install it on your Mac. This process will take more time than the regular update process. Now, put your Mac in Recovery mode [Intel or M1], Start installation of macOS Monterey from External Bootable USB drive.

Fix 12: Possible error due to BridgeOS update issue

To resolve the problem, I suggest you create a new partition and install Monterey using an External Bootable drive that’ means clean install of Monterey (macOS 12) without affecting data saved on other partitions on the same mac.

installing from a boot disk, installing in recovery mode, safe mode, internet recovery mode.

Fix 13: Disabling the Gatekeeper on Apple Mac, that helped me

Last Solution– Wait for few days and try Trying the public beta profile download on your Mac.

Hintinstall macOS Monterey on external SSD

Fix 14: Command Terminal

Open Terminal. Copy and Paste and enter:

sudo nvram IASUCatalogURL=

You might need to enter two times if you got the error.

After that, rerun the installer –> It worked.

After done upgrading, you should update the NVRAM back:

sudo nvram -d IASUCatalogURL

jaysukh patel

Jaysukh Patel is the founder of howtoisolve. Also self Professional Developer, Techno lover mainly for iPhone, iPad, iPod Touch and iOS, Jaysukh is one of responsible person in his family. Contact On: [email protected] [OR] [email protected]

We will be happy to hear your thoughts

Leave a reply