macOS Big Sur 11 – List of Install & Upgrade Issues

Monday, November 16, 2020 2:23 AM

macOS Big Sur 11 – List of Install & Upgrade Issues 



This article is a running list of all known macOS Big Sur install / upgrade issues.

macOS Big Sur launched on Thursday November 12th, 2020. As with any launch of a product or software there will be issues. In the case of Big Sur, the problems started almost immediately. Users started to report download issues when trying to get Big Sur. 

As the the week went by, more serious issues started showing up. If you are seeing a one of these issues, feel free leave a comment below.



1. Big Sur Full Installer.app Download Problems – “Installation Failed Error Occurred while installing the selected updates.”

This issue started around 2:00PM CST on Big Sur Launch Day. Users started to see this error message when trying to download Big Sur.


Big Sur Download error.



2. Big Sur progress gets stuck mid installation – Black Screen with Apple Logo stuck or stopped progress bar

This issue happens halfway through the Big Sup upgrade or install process. The Mac has already rebooted to the installer and is now on the progress bar. The problem is, something has gone wrong on the install and the progress bar gets stuck at a certain percentage and will never move again. 

The progress bar looks to gets stuck at around 40% or further and will never move again. 


Big Sur install Black Screen progress bar stuck.


What should you do if this issue happens to you?

  • 1. First WAIT! Sometimes the install process takes time. If after a few hours pass and the progress bar has not moved go to the next step.
  • 2. At this point, you have no choice but to power down. I know this sounds drastic, but you literally have no other choice. The good news is, this is also the fix. Many users have reported that this fixes the issue for them. After force powering down the Mac will come back up and and will boot right to Big Sur.
  • 3. If the progress bar still comes up your problem might be something else. I recommend holding down shift for safe mode. If this works reboot again to see if you still get stuck. – 

3. Big Sur Install bricking some older 13″ MBPro’s

Out of all the reports, this one is the most serious. I do not throw around the “Bricking” term much, as it means that the Mac is usually DEAD. In this situation, if this issue happens to your Mac it will be non responsive.

The reports say that the install starts but after the reboot they get a black screen with nothing on it. Even if the user restarts they will still get the black screen. If they attempt to hold down option, Command R, Reset the Pram, SMC… etc nothing works. In this mode the Mac will NOT respond to any startup keyboard commands

Affected Macs known so far.

  • 13″ MacBook Pro from 2013-2014.

What should you do if this issue happens to you?

  1. Wait until a possible new fix comes in.
  2. Bring it in for repair.


4. Big Sur stuck in endless boot loop

Other users have reported that after installing Big Sur, their Mac will be in an endless boot loop. 

What should you do if this issue happens to you?

  • 1. Try to boot into safe mode. Does the the Mac boot correctly? If so something installed on your mac is causing this issue. Maybe it’s an 3rd party application that has installed a Kernel Extension or a LaunchDaemon that is causing the issue.
  • 2. Reinstall macOS
  • 3 Bring it in for repair

5. Slowness after upgrade to Big Sur – Other have reported that their Mac is very slow after upgrading to Big Sur.

I am starting to see a decent amount people say that after updating to macOS Big Sur from macOS Mojave or Catalina has caused a bunch of weird issues including slowness. The slowness is all over the system, including opening apps, Apple Menu and system preferences just taking a long time to load.

What should you do if this issue happens to you?

  • Wait! It’s possible that spotlight search is currently indexing and can take some time.
  • If after a while the system is still slow, open up activity monitor and click on the CPU or Memory tabs. Are any apps or processes taking very large amounts of memory or CPU?
  • If so kill the process then check system performance.
  • Still having issues after checking everything? Backup your data and perform a fresh install. 
  • We have macOS Big Sur running on a bunch of Macs even all the way back to the 2013 model. They all run very well. Almost all of them had a fresh install. This might be the way to go.