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[macOS Big Sur] How to Fix macOS Update Stuck Error

Each time a new Mac desktop operating system updates, a flood of Mac users would rush to download and install the macOS. There is no exception for macOS Big Sur, which has just been released as a free upgrade for users. It features with many significant changes or redesigns in Big Sur compared to Catalina, including the new design, Messages new features, faster Safari, enhanced apps, etc.

Many users reported that macOS download stuck, installation failed, an error occurred while installing this update, installation stuck on grey/space screen or failed issue when they attempt to get it upgraded. Concerning such miscellaneous macOS Big Sur update stuck issues, this article covers a collection of macOS Big Sur update failed problems and solutions.

Read more: macOS Big Sur update guide and quick fixes to any Big Sur update problem.

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What Should do Before Upgrading to macOS Big Sur?

Although the every new macOS upgrade comes with certain exciting features, you need to know if your Mac computer can safely be updated (take Big Sur as an example). If you pay no attention to the details, macOS Big Sur update problems come with you for sure, probably your Mac update stuck or Mac failed update won't boot. Here are some of the things that you should look for before you upgrade to the new update.

1.Check compatibility. Big Sur requires any of the following Mac models: iMac; MacBook Pro; MacBook Air; MacBook; Mac Pro; Mac Mini.
2.Check minimum software and hardware requirements. You should have OS X Mountain Lion 10.8 or later. It requires at least 35.5GB of storage space to perform the Big Sur upgrade from macOS Sierra or later, 44.5GB from an earlier release.
3.Backup your Mac. To avoid any possible macOS Big Sur update problems, making a backup of your Mac comes essential. You can backup Mac with Time Backup Machine, iCloud, iTunes, or any other third-party Mac backup tools like MacX MediaTrans.

Common macOS Big Sur Update Stuck Problems & How to Fix Them

macos big sur update download stuck

1. Big Sur Update Download Stuck

As you attempt to download macOS Big Sur installer, you may be noticed that "Installation requires downloading important content. That content can't be downloaded at this time. Try again later.", or "An error has occurred." Big Sur download times are slow this year and are always failing. It's exceedingly annoying, but there is no way to bypass this step for macOS update.

Usually Mac update download failed error is originated that you download the package from somewhere other than Mac App Store or you just downloaded the Beta version. So you need to go to Mac App Store and download the official macOS Big Sur instead to fix it. Overloaded Apple's server is also a main cause.

macos big sur installation failed

2. macOS Big Sur Installation Failed, An Error Occurred

Installation failed, an error occurred while installing this update while upgrading to Big Sur. It got to about 10% or halfway and failed, some users cannot even reconnect. Many users are getting the same error. The macOS Big Sur installation failed error is properly caused by overloaded Apple's server, there are tons of users rushing to download now. You can check on the status on Apple's support system status page. Wait for a while and try again.

Apple resolved the issue, however, some users still get macOS Big Sur installation stuck message. Read more: What to Do If macOS Big Sur Installation Stuck/Frozen/Slow

mac update failed

3. Failed to Update macOS Owing to Insufficient Storage

You know, Big Sur update requires at least 2GB RAM and 14.3GB available storage. So if your Mac computer almost ran out of the storage space, your macOS update stuck at the beginning for sure. To make sure how much space your Mac has left, from the Apple menu, select About This Mac > More Info > Storage.

If your Mac update failed definitely owing to the storage space, the only thing you need to do is to free up the space on Mac. Just make it done by uninstalling unused applications and app caches, deleting old devices backups, deleting unnecessary media files from iTunes, emptying trash can, clearing temporary files, compressing large files to smaller size and so on.

mac update freeze on verify firmware

4. macOS Big Sur Update Freezes on Firmware Confirmation

The inability to verify firmware error is the mainly reported macOS update problems. Many users said as they try to update to Big Sur, the installer noticed that there is an error checking the firmware. Actually, it turns out to be a corrupted EFI partition. It's an MS-DOS formatted little slice that's needed when updating the computer firmware.

You can boot into rescue mode, checked the partitions with "diskutil list" and "verifydisk" (terminal), and fixed the EFI partition "diskutil repairdisk (your EFI disk/partition) ".

macos Big Sur update installation stuck

5. Big Sur Update Installation Stuck with DiskManagement Error

After downloading the new macOS for my MacBook pro (mid-2012) with HDD, the computer restarted but continues to fail during the installation. The error I keep getting is . I completed a disk repair but no errors popped up there, so I assume nothing is wrong with the drive. I tried to reinstall macOS from recovery mode, but I continue getting this same error. Does anybody know how to fix this problem? - Apple Support

As the DiskManagement Error happens, you can try to fix it within the following steps: 1. Start in recovery with ALT+CMD+R > 2. Go to disk utility > 3. Convert the volume to APFS > 4. Restart the installation

mac update stuck on gray screen

6. Big Sur Update Stuck on Gray Screen

It's not always a gray screen, as strange as that may sound. The "gray screen" problem can also manifest itself as a black screen, space screen with Apple logo, a spinning gear, a spinning globe, or a prohibitory sign. Mac update stuck on gray screen problem can occue right after you start or restart your Mac. It may be caused by a bad peripheral or peripheral cable, RAM issue, Drive issue or whatever.

Before you start to fix the macOS update stuck on gray screen problem, you need make sure what's the cause. Then you can disconnect all external peripherals, remove all but the minimum amount of RAM from your Mac, use Single-User mode to repair a Startup Drive. I think the problem will be fixed.

After you have fixed the macOS Big Sur update stuck problem, you can enjoy the salient new features of Big Sur. But at the same time, some new troubles might trouble you as well, such as like macOS Big Sur running slow, some apps get damaged or non-Apple Apps cannot be opened, Safari crashed, Mac gets overheated, or the Big Sur keeps logging you out etc. So think twice before you upgrade to macOS Big Sur, and if you encounter any Big Sur update problems, pick the macOS update problems and fixes as a reference.

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