What to Do If Your macOS Big Sur Installation Failed/Stuck/Frozen/Slow

Posted by Winnie to Mac, Apple Resources | Posted on Nov 13, 2020

Can't complete macOS Big Sur update because of being interrupted by Installation failed: an error occurred while installing the selected updates? Your Mac installation stuck/frozen or is slow when you're upgrading to macOS 11 Big Sur? Specifically, your Mac install stuck on Apple logo with a status bar showing the progress as the software is loading; Mac update stuck on gray screen, white or black screen; or your macOS update is extremely slow. What to do if your macOS Big Sur installation can't be completed, get stuck, frozen or extremely slow? Here we'd like share you some tips to fix Mac installation stuck problem.

macOS Big Sur Installation failed error

Backup your Mac before installing Big Sur

Lest Mac Installation Stuck, Backup Your Mac in Advance

Given that your macOS installation stuck or frozen on the half way, you need to forcibly reboot the Mac which will interrupt the installation process and potentially cause you to lose data. So utilize MacX MediaTrans to back up photos, videos, music, ringtone, ebook, etc on your Mac before you install new macOS Big Sur.

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Make Sure Your Mac Installation Got Stuck/Frozen Really

At the very beginning you need to check whether your macOS update get stuck because the macOS upgrade can take a very long time. Usually several hours are needed, but there are exceptions as well. Sometimes update can take 16 hours or more. So it's quite essential to see the Log to make sure whether your Mac is still installing macOS Big Sur normally.

Just press Command + L, you can see the detailed remaining time of the whole Mac installation, what files have been installed, what files will be installed next and the amount of time left. If the Log screen shows that nothing is happening, your Mac installation stuck/frozen indeed.

Tip & Tricks to Fix Mac Installation Failed/Stuck/Frozen/Slow Errors

If your Mac is unable to install macOS Big Sur or freezes on installing, you can try to fix it with the following tips. There is no guarantee that each tip works on macOS update problems. But it covers the common measures when Mac users fails to install new macOS, hopefully any of these tips will work for your macOS installation problem.

1. Shut down your Mac and wait for some time. When a new OS releases, a massive number of people will go to download and install the updates in a snap. As a result, the downloads and installation will be very slow with the large file and many people doing the same thing at the same time, and even fail during the process. What you should do is to wait for the server becoming less busy. According to Apple system status page, macOS Software Update issue has been resolved. Now you should download the macOS Big Sur update file faster and install it without seeing "An error occurred while installing the selected updates"message.

2. Go to Mac App Store and open updates. If your Mac install stuck on Apple logo, gray/white/black screen when you were installing an App, you can go to Mac App Store to find this app and open the updates to survive from the macOS installation stuck situation.

3. Download & install the combo update. The Mac App Store isn't the only place to download macOS from. When your encounter problems on macOS Big Sur installing, you can try to download the combo macOS update from the Apple official site because the macOS installation package downloaded from Mac App Store may only include the essential files for your Mac update, instead of the combo updater with all the files required to update to macOS.

mac-installation stuck

4. Install in Safe Mode. Safe mode (also called safe boot) is a way to start up your Mac so that it performs certain checks and prevents some software from automatically loading or opening. When your Mac installation stuck or Mac runs slow when Big Sur installing, you can install in Safe Mode so that you're able to resolve issues that might keep your Mac from completely starting up, or to isolate other issues related to your startup disk. Simply press the power button and hold down the Shift key to start the Mac up in Safe Mode. Open App Store and update your apps while in Safe mode. Reboot.

mac installation frozen

5. Clear Mac Storage Space. If your Mac doesn't have enough space, the macOS Big Surinstallation can be stuck or slow as well. So before Big Sur installation, you should free up your Mac space to solve the Mac installation stuck problem. There are many tools to make this done, and MacX MediaTrans absolutely deliver the double benefit of clear Mac space and make a backup of your significant files.

macos installation slow

6. Reinstall macOS with Recovery Mode also works for Mac installation frozen error. But to be frank, it's the least option, since there is a possibility to loss your Mac data. To adopt this solution, you can hold down Command + R at start up. Then recover your Mac from last Time Machine backup, or from iTunes and iCloud backup.

7. Install macOS from the External Hard Drive. Well, if you're still having issues with the install you could try installing the OS from an external drive. This sounds unpractical, right? But if you actually install macOS Big Sur on an external drive, flash drive, or SD card, you can use the external hard drive for Mac as the macOS system disk wherever you go. To make this done, you need an external storage device with a minimum capacity of at least 16 GB (though the larger the better) and a copy of the macOS 11 Big Sur installer.

Finally, when you get the macOS Big Sur installed, we advise that you run Disk Utility to correct any issues that might have caused the problem in the first place. Simply, click on the Finder Icon from the dock; locate and click to open Applications within the left pane of the Finder window; scroll to the bottom of the Applications window to locate and click to and open Utilities and locate and click to open Disk Utility.

Make A Backup of Your Mac with MacX MediaTrans!

MacX MediaTrans, an awesome data transfer tool between Mac and iOS, allowing you to transfer significant Mac files, like video, 4k photos, music files, videos, ringtone etc. so as to make a backup of Mac data and free up more space on MacBook Pro/Air, iMac etc.

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