How to Fix macOS Big Sur Installation Failed

Wondering how you can fix your failed macOS Big Sur installation?

The macOS Big Sur is an exciting new update for Mac users. With new features, an optimized interface, and more, there’s a lot to look forward to from Apple’s latest upgrade to the Mac.

Unfortunately, if you’re reading this article, then you’ve probably run into the “Installation failed. An error occurred while installing the selected updates” error.

We understand the concern and annoyance that comes with this, but don’t worry as there are a couple of solutions that you can do to try and fix this problem. In this article, we’ll be guiding you through several methods to fix your failed macOS Big Sur installation.

Let’s get started!


1. Foreword.

The new macOS Big Sur update is a massive upgrade from your current or past version of macOS. Due to that, you can expect that a lot of people are trying to update their macOS at the same time as you, which hinders and overloads Apple’s servers.

Since the servers are overloaded, there usually is nothing you can do on your end to try and fix this problem. Despite that, we’ll still provide you with four technical methods that you can try to hopefully fix this issue.

Additionally, we’ll also provide a link below to help you get in touch with Apple’s customer service so you can let them know you’re having this issue.


2. Check Apple’s Servers.

First, we recommend checking Apple’s servers so you can verify for errors or issues before proceeding. If Apple’s servers are indeed down or facing issues, chances are you probably won’t be able to download the update at this time.

Although a large majority of Mac users have been reporting success with their updates over the last couple of days, it’s still possible for these servers to be overloaded for you. To check and see the status of Apple’s servers, simply go to their System Status page on their official website.

From there, look for macOS Software Update and see if the server is available. This should be indicated by a green circle. If the server is up and running, then let’s proceed to help you install and fix the software problems that could be arising from your end of this issue.


3. Restart Your Mac.

A quick reboot fixes most software issues, especially the ones related to your operating system. By restarting your Mac, you’ll be terminating and rebooting all software processes thereby ironing out any glitches or bugs.

Here’s how you can restart your Mac:

  1. Go ahead and click on the Apple icon at the top-left corner of your screen.
  2. From there, simply click on Restart and wait for your computer to shut down and reboot.

Once that’s done, try to update your macOS version through the software update method. Hopefully, your macOS Big Sur will begin downloading, and you’ll no longer receive the “Installation failed. An error occurred while installing the selected updates” error.


4. Refresh Your Software Update.

Before installing the update, a lot of users have found success in refreshing their Software Update window. Thankfully, this is pretty easy to do and should be a straightforward fix to this annoying problem.

We suspect that by refreshing the Software Update window, perhaps this refreshes your connection to the Apple server as well. This might help you avoid congested servers by having your Mac connect to a less populated server.

Here’s how you can refresh the Software Update window on your Mac:

  1. Start by opening up the Apple icon on the top-left corner of your screen and select System Preferences.
  2. Now, go ahead and click on Software Update.
  3. Once you’re there, press the Command + R keys together to refresh your Software Update window.

macos big sur installation failed

  1. That should be all you need, go ahead and click on Upgrade Now so you can try and install the macOS Big Sur update.

Thankfully, if this does work, then simply wait for the 12GB of files to finish downloading. The process from there should be pretty intuitive. Hopefully, that helped fix your failed installation of macOS Big Sur.


5. Download Through The Mac App Store.

You don’t have to limit yourself to just installing the macOS Big Sur through the Software Update window. Thankfully, you can also get the new macOS version from the Mac App Store itself.

The steps for this are quite simple and is a great alternative to try, especially if the Software Update servers are congested. This should hopefully give you a better chance of downloading the new update successfully.

Here’s how you can download the macOS Big Sur through the Mac App Store:

  1. There are two ways that you can go about this step, so feel free to do whichever is comfortable for you:
  • With your browser already open, simply go to the Mac App Store Webpage and click on View in Mac App Store.
  • Alternatively, you can also open the App Store at the bottom-right side of your System Tray. From there, look for ‘macOS Big Sur’ on the search bar at the top-left corner of the App Store.

macos big sur installation failed

  1. Once you’re there, simply click on Get.
  2. Finally, you might be asked to confirm the download, just click on Yes and continue the installation.

Hopefully, that helped you fix your macOS Big Sur installation. If you’re still having a problem, go ahead and proceed to the next method on this article for the next fix.


6. Download At Midnight.

With all the methods above failing, you may want to reschedule your update to a much later period. Chances are, the servers you’re connecting to must still be congested which is giving your update a hard time.

macos big sur installation failed

We suggest waiting until midnight or a little past midnight to install the update since most individuals should be asleep by then. This way, the servers will not be subjected to lots of traffic which should help you download the new update.


7. Wait A Couple Of Days.

Finally, if you’ve stayed up last night and still haven’t had any success with all the methods above, you might want to give this a couple of days. The new update still has a long waiting line with everyone waiting, just like you.

By waiting for a couple more days, the line will eventually decrease. This leaves you as one of the few thousand people who can download the update without traffic and congestion.

How to enable internet sharing on Mac

Still, if this didn’t work, then it might be in your best interest to contact Apple’s Customer Support team to let them know that you’re still facing the issue. Perhaps they can do something on their side to help you connect to the servers or refer you to their professional technicians.

Alternatively, try disabling any third-party VPN programs on your Mac to see if that makes any difference. Here’s how you can disable your Mac’s default VPN service.

That about wraps up this article. Hopefully, we’ve helped you fix your failed macOS Big Sur installation. With no more “Installation failed. An error occurred while installing the selected updates” errors, leave us a comment down below if you have any questions or clarifications.

If this guide helped you, please share it. 🙂


  • Mako Young

    Mako is a staff writer at Saint. He's been writing about tech for more than a decade. When he isn't reading about the latest news on Apple, he's busy studying cybersecurity, cryptocurrency, cloud computing, and other IT-related sectors. His exceptional work graces technology and Apple-related blogs like How-To Geek,, Macgasm, onMac, PhotoWorkout, GameRant, and many more. He also has a Bachelors in Computer Science and has been writing since 2018, with over 400 posts published. LinkedIn X (Twitter)

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