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[Updated] How to Upgrade to macOS 11 Big Sur and Fix Any Big Sur Update Errors?

MacOS 11 Big Sur is the biggest update to macOS in years, with massive performance improvements, ARM Mac transition support, new features, and a lot of app enhancements to get excited about. All the benefits are a strong reason to upgrade to Big Sur. The final stable version will be available in the fall, and you can just wait for another week for the public beta. At present, you can only download and install the macOS 11 Apple Developer Program, which is priced at $100. Below we will show you how to download and upgrade to macOS Big Sur.

Can I Get macOS Big Sur update on My Mac Computer?

You can upgrade macOS to 11 Big Sur if you're running any of the following device:

  • MacBook Pro (Late 2013 or later); Mac mini (2014 or later)
  • iMac (2014 or later); iMac Pro (all models)
  • Mac Pro (2013 or later)

Back up Your Mac to Avoid any Big Sur Update Problems

Any bugs and problems can happen during Big Sur update. And any download/install failure may cause data loss. Therefore, you're suggested to back up the important data saved on your computer. You can back up Mac to an external hard drive or other cloud storage services. Below we'll take Mac's built-in backup feature Time Machine as an example:

  1. Connect an external hard drive to Mac. Make sure the hard drive has enough space to store your Mac.
  2. Click System Preferences > Time Machine > toggle the switch from "Off" to "On."
  3. Then click the Select Disk… to select the hard drive. Then it will start to backup Mac.

Note: Time Machine is a complete backup solution, which requires large space and long time. If you only need to back up some important data, there are many third-party Mac backup tools and services to help.

How to Download and Install Big Sur

  1. On your Mac, go to https://developer.apple.com.
  2. Click the Discover tab > click the macOS tab at the top of the page.
  3. On the macOS page, click the Download button at the top right corner and sign into your Apple developer account (if you don't have a developer account, click Member Center> sign in with your Apple ID > on the Apple Developer Agreement page, check the box to accept the agreement > click the Submit button. Then your Apple ID is a free developer account).
  4. Click the Install Profile button at the bottom of the page to download macOS Big Sur.
  5. Find and launch the installer of macOS Big Sur Developer Beta Access Utility. Double-click macOSDeveloperBetaAccessUtility.pkg to run the installer.
  6. When the installer downloads, System Preferences will check for an update to MacOS. Click Update to download and install macOS Big Sur beta.
How to upgrade to macoS Big Sur
Download and install macOS Big Sur

macOS 11 Big Sur Update Problems and Fixes

Update to macOS 11 Big Sur is not always smooth. Some known issues already happen during the download and install. First of all, let's exclude some basic reasons that may cause Big Sur update errors. First of all, check if your Mac is compatible with the new system; second, make sure your Mac has enough storage for Big Sur. Open the Apple menu and click About This Mac > select Storage and check if there is at least 16GB free space.

1. macOS Big Sur installation failed

"An error occurred while installing the selected updates.". This happens not only to you, but almost everyone. The official explanation from Apple is Apple widespread outage to blame. You have no choice but to wait the Apple official fix.

macOS Big Sur installation failed
Big Sur intallation failed

2. macOS Big Sur update bricks some old MacBook Pro

This issue is widespread. Currently, stop updating to Big Sur or patiently wait for the official fix for macOS 11 Big Sur. When Big Sur is optimized, upgrade then.

3. Deleted emails are instantly deleted from server, not going to trash

Try contacting Email service provider to restore your important Emails. Or use some Email recovery software to get them back. Currently, no official solutions are provided. It's not a wise decision to update to macOS Big Sur right now. Downgrade to your previous version or macOS Big Sur if you don't want to suffer more pesky problems caused by Big Sur update.

4. macOS Big Sur update not found

You're not alone to endure such a pesky macOS 11 update error. To turn it around, try fixing this issue by following a link to download from the Mac App Store and then starting the download via the Software Update control panel afterwards.

macoS Big Sur update not found
macoS Big Sur update not found

5. Big Sur download is stuck

Updating to macOS Big Sur 11 beta from previous macOS Big Sur might take significantly longer than expected. Data loss could occur if the update is interrupted. There are other users who tried to download Big Sur installer via system update for hours. But Big Sur download stuck in the middle without progress.

  • Shut down your computer, restart it and hold down the shift button until it starts in safe mode. Then redownload Big Sur.
  • Restart/refresh your Internet connection to avoid any network connectivity errors.

6. Incredibly slow download for macOS Big Sur

There is high likelihood that Apple servers is overwhelmed. Give it sufficient time, wait patiently, or simply cancel the download. It might be much better to re-download macOS Big Sur tomorrow since by then Apple has more server capacity available to accommodate the demand.

7. Software update forbidden

Confronted with an error message forbidden - An error occurred while installing the selected updates? So far, the reason is complex. For some users, they remove beta version from macOS and re-download macOS Big Sur to get it fixed. For others, reboot their MacBook or iMac seemingly workable. If you're still in trouble, possibly contacting Apple support is the way to go.

macoS Big Sur update forbidden
macoS Big Sur update forbidden

8. macOS Big Sur update not enough free space

There are a lot of complaints that after download the software, it won't install and says "There is not enough free space on the selected volume to upgrade the OS. An additional GB.MB is required". However, there are enough storage avaiable on users' computer. If you have the same Big Sur update problem, try this:

  • Clear the local snapshots of Time Machine stored locally on your Mac. To do this, choose Apple menu > System Preferences, then click Time Machine. Turn off "Back Up Automatically". If that doesn't work, then delete the snapshots manually in the terminal: type tmutil listlocalsnapshots / and then type sudo tmutil deletelocalsnapshots 2020-06-01-002010;
  • Sign out from AppStore -> Restart Mac -> Sign in to AppStore -> Download Xcode;
  • Download the installer on an external hard drive and try again.

9. Big Sur not connecting to Wi-Fi

"I've updated to Big Sur and I'm having trouble when connecting to WiFi networks. At first no network appeared and now even though it has connected silently to my usual network, it is showing as no connected, but internet actually works." For Big Sur WiFi problems, you can try:

  • Switch Location in the network preferences menu to somewhere else and try again;
  • Remove the WiFi from the Network pane, reboot and reset SMC, then add the WiFi back.

10. Can't open apps after update

There are users reporting that they can't open apps or apps crash on startup after they upgrade to macOS Big Sur. The failed apps include Messages, Dropbox, Mail, Safari, Finder, Airdrop, etc. When you have similiar problems, try to:

  • Install the new Xcode Beta;
  • Check if there is a new app update;
  • Delete every internet account from the System Preferences panel (except iCloud) and create new ones. 

11. Menu bar items disappearing

After update to Big Sur, the new control center, WiFi and other system icons in menu bar are disappeared. What happened and how to get the missing icons reappear?

  • Turn off fast user switching: System Preferences => Dock & Menu Bar => Other Control Center Mod... => Fast User Switching, and uncheck both checkboxes.
  • Try to run it from Terminal: sudo /System/Library/CoreServices/ControlCenter.app/Contents/MacOS/ControlCenter

12. macOS Big Sur battery drain

Some users from Apple community and reddit complained that Mac computer is showing battery health dropped 10% or even more in less than one week after installing macOS Big Sur. Here are some proven tips to solve the problem with Big Sur.

* Disable some apps. Big sur features updated and new apps that are supposed to exert pressure on your computer. You can use Activity Monitor to check the apps that are draining battery greatly, and disable them for see if it is fixed. Some users from reddit reported that battery life was improved significantly when Chrome helper app and the entire drive from Spotlight scanning are disabled.

13. Cannot connect to any bluetooth device on macOS Big Sur

There are still many users experiencing difficulty with connecting to any Bluetooth device or suddenly everything drops connection to Macbook after updating to macOS Big Sur. Here are some fixes for Bluetooth problems that are also feasible for other macOS updates.

Press Shift + Option, and then click on the Bluetooth icon in the menu bar, select Reset the Bluetooth module and then restart your Mac to see if the problem is fixed.