[Solved] How To Fix An Error Occurred Installing macOS Big Sur Issue

Author Spencer Mcfadden By Spencer Mcfadden, on November 12, 2020, in macOS Problems | SOLVED

Summary: [macOS Big Sur Problems] Trying to upgrade your Mac to macOS Big Sur but getting An error occurred installing macos Big Sur? Check out our complete tutorial on how to fix An error occurred installing macos Big Sur issue. Get Omni Remover Free >

Get Omni Remover

Best Mac App Cleaner

100% Free & Secure Download

macOS Big Sur is arriving this week with an array of new and exciting features that users may be eager to have a try. As usual, Apple is providing an early version of this macOS Big Sur beta release to both developers and RC version for testing users. Somehow a small group of users told us the macOS Big Sur upgrade is not always smooth. One common macOS Big Sur issue during the update is that - An error occurred installing macos Big Sur. You can follow the instructions below to get fixes on An error occurred installing macos Big Sur issue.

How To Fix An Error Occurred Installing macOS Big Sur Issue
How To Fix An Error Occurred Installing macOS Big Sur Issue

UPDATE 1 - Apple Confirmed Problems With macOS Big Sur Software Update (November 12, 2020): The installation setup files for macOS 11 Big Sur is roughly 12GB in size and will take couple minutes or even half an hour to download. But even users with fast to very fast internet service, they may see estimates of 12+ hours or even 7 days to download macOS Big Sur. Especially on the first day of public release, a large amount of user are experiencing macOS Big Sur Install and Download issues.

UPDATE 2 - Apple Announced Fixes on macOS Big Sur Won't Install/Update Issue (November 12, 2020): Even after Apple acclaimed the macOS Big Sur software update problem has been fixed, users are still seeing an error after Big Sur is downloaded preventing it from being installed. Our dev teams and contributors on MiniCreo community are still looking for solid solutions on this matter.

Common macOS Big Sur Software Update Won't Install Cases:

  • Solved - An error occurred while installing macOS Big Sur updates: When you failed to complete the macOS Big Sur update, and see a warning message - An Error Occurred Installing macOS. You can try again to complete the installation, it could be that the macOS Big Sur downloads are extremely slow or failing due to a developer site issue or the developer site could be failing under the strain of ‌macOS Big Sur‌ demand.
  • How To Fix An Error Occurred Installing macOS Big Sur Issue
    How To Fix An Error Occurred Installing macOS Big Sur Issue
  • Solved - macOS Big Sur Installation failed: In addition to these Big Sur download problems, Apple's developer site is also down at this time, and as a result, some third-party apps are unable to be opened up at this time.
  • How To Fix An Error Occurred Installing macOS Big Sur Issue
    How To Fix An Error Occurred Installing macOS Big Sur Issue
  • Solved - Others are experiencing unusually slow macOS Big Sur load/download speed before the installation aborts. "MacOS Big Sur won't install. Been waiting three hours only to get this (error) message," one user tweeted.

Best Free Mac Cleaner & Uninstaller

#1 Solution For macOS Big Sur Won't Install Issue

Fix Up To 50+ Big Sur Software Bugs and Glitches

Smooth Your Way for macOS Big Sur Upgrade

Get Omni Remover

Best Mac App Cleaner

Most Common macOS Big Sur Problems and Best Fixes 2020


Part 1: Check macOS Big Sur Download Server Availability

Apple has confirmed the macOS Big Sur download slow or failure issue on its System Status page saying “Users may not be able to download macOS Big Sur Software Updates on Mac computers. The issue is currently being investigated.” By checking Apple System Status, you can also check if it's the server issue with iMessage, Safari, or other apps not working on macOS Big Sur.

How To Fix macOS Big Sur Not Installing/Downloading Slow
How To Fix macOS Big Sur Not Installing/Downloading Slow

Get Omni Remover - macOS Big Sur Won't Install Error

Part 2: Free Up Space On Mac Before Installing macOS Big Sur

As mentioned, the macOS Big Sur initial installation setup files is roughly 12GB in size and will take double size to complete the install. We are seeing estimates of 12+ hours all the way up to 7 days in some cases. However, as a matter of fact, the macOS Big Sur download speed is really slow. But even users with fast to very fast internet service, it's not easy to reclaim 20+GB storage space on your Mac hard drive disk. So give a try on the following tips to free up space on your Mac for installing macOS Big Sur smoothly.


How-To Steps To Free Up Space On Mac Before Installing macOS Big Sur:
  1. 1
    Step 1:

    On macOS Big Sur, Storage Management option offers recommendations for optimizing your Mac storage. If some recommendations are already turned on, you will see fewer recommendations.

    How To Free Up Space On Mac Before Installing macOS Big Sur Step 1
    Step 1: Use Storage Management
  2. 2
    Step 2:

    Uninstall useless applications. By using Omni Remover, you can clean uninstall bloated apps, plug-ins, and extentions.

    How To Free Up Space On Mac Before Installing macOS Big Sur Step 2
    Step 2: Use Omni Remover

Get Omni Remover - macOS Big Sur Won't Install Error

The Bottom Line

Now can you fix the macOS Big Sur won't install issue with our suggestions above? If you still have further macOS Big Sur problems or bugs, feel free to contact us and we are happy to help. In addition, we will keep updating our macOS Big Sur Porblems list so that to cover all upcoming software/hardware glitches on your Apple devices.


MiniCreo / Mac Problems / Omni Remover / An Error Occurred Installing macOS Big Sur

Omni Remover

Requirements: OS X 10.8+ , 13.1Mb free space
Version 3.3.1 (November 12, 2020) | Support macOS Big Sur | Category: Mac Uninstaller

More iPhone Problem Fixes and Tips

Tags: iPhone Data Recovery   iPhone Transfer   iPhone Fixes