An Error Occurred Preparing The Software Update - Macbook Pro

Big Sur downloads
restarts then tries to install and gets stuck at 10%, giving the error you see below
Trying to start in recovery then asks for your password, which the Mac tells you is incorrect
Trying to enter your vault key from iCloud doesn’t work either because it tells you your “iCloud account cannot unlock this volume“
There is no way to get to a main screen or any screen; no way to recover or enter your password for anything
Spent 2 hours on the phone with Mac support: we finally were able to to get it to a Utility screen by pressing “Shift + Option + Command + R” at the same time immediately after hitting the power button, wait a long time for it to start up; where you will see a world icon with a bar or timer under it; took about 15 minutes
In the utility screen settings, when they finally appear after having to re-enter your password for your Mac; and I found out what was wrong; my Macbook didn’t have enough space; you can see in the below screenshots
Big Sur is 13GB. My Macbook Pro had 9.5GB of free space; normally, Big Sur would not have downloaded knowing it didn’t have enough space… but that didn’t happen, so it tried to install itself anyway, and got stuck
Now, there is no way to clear space; the hard drive section in Utilities is missing so we cannot reset the OS (Operating System) to an older version
Apple Support said take it to an authorized Apple Repair shop; so I did
Took it to a Mac specialist locally and they said they have no idea how to fix it; but they would have to wait 3-5 days likely at minimum before Apple released a resolution, also a lot of people are having this issue
You need your laptop for work or school, so this is debilitating, I feel you.

Connecting Your Mac To Another Mac For Recovery

You can try this; but both Macs have to be the same hardware/version.

The Supplied iCloud Account Was Unable To Unlock This Version

“If you can’t log in to your computer because you forgot your password, you can reset it now”. Trying to recover your Mac using your iCloud account will not work either, it just gives you this error message.

Using MacOS Utilities To Restore from Big Sur Update To Catalina or Earlier Version

Time Machine – this only works if you had been saving everything you do on a backup device, like a second hard drive that you attached to the Macbook. If you haven’t been, this is not going to work.
Reinstall MacOS – It fails; but if it works it means you lose everything not saved in the cloud or on a backup drive
Disk Utility – It is not showing the necessary hard drive in order to clear space or reset the OS (Operating System)

Go to Utility screen by pressing “Shift + Option + Command + R” at the same time immediately after hitting the power button, wait a long time for it to start up; where you will see a world icon with a bar or timer under it; took about 15 minutes and it brings you to this….

Not Enough Space For The Big Sur Mac Update

So, I finally found out that the reason Big Sur is not installing is that there was barely enough space. However, there is no way now to clear the space. I am at risk of losing anything that wasn’t saved in the iCloud now.

Resolution So Far (Nov 20th, 2020)

Had to take it to a Mac repair shop, Mac Phone Support could not figure it out; the Mac repair shop needs 3-5 days minimum. I am looking at buying a replacement Mac in the meantime. The new Mac M1 chip laptops seem like a good choice, and to have a backup back for future issues.

Jan 15th, 2021 – Macbook Big Sur Error Update

I had to erase my drive, reinstalled Catalina operating system, then upgrade to Big Sur. I lost my drive completely, and everything on it. Since I didn’t have Time Machine or anything that wasn’t on the desktop backed up, I lost 2GB of data from the past 2 years.

Now I have a desktop and laptop and have them synced, and I got the apple’s Time Machine backup going in case it ever happens again.

Thomas J. Kane

At 16 years old in 1997 I built my first client website for a car dealership. At 17 I was one of the first few people in Kansas to be Cisco Networking Certified and I helped co-build the first computer network for a high school, two elementary schools, a hospital, and a 911 station. By the age of 40 now I have over 25,000 hours in content writing mastery and Google Advertising/SEO and have worked with over 480 different industries, amazing mentors, SEO & PPC corporate team leader at Godaddy.com, trained other SEO company's staff, managed over $37M dollars in advertising spend since 2007 for multiple companies and spent over $1M in A/B testing, created landing pages, sales funnels and massive PPC campaigns for the USA's #1 automotive leads provider, helped expand a global e-commerce business from 5 English sites to 122 sites in 30 countries in 7 languages, owned two #1 top-ranked SEO companies, in both Arizona & Kansas. Won all-expense-paid trip awards from Google for PPC performance, and been to the headquarters in Boston and California, and worked with 3 dedicated senior Google PPC teams at 3 major companies. I run an online advertising service for Montana, Kansas, Arizona & Florida businesses, as well as manage large campaigns for online national stores and services. Into renewable energy, solar, wind energy, crypto currency, Tesla, Nikola, natural health and healing, traveling, psychology, human behavior analysis, lie detection, forward progress, inspirational and educational writing, research, and analysis. Fascinated with AI (https://thomasj.ai/) and how it relates to the future of search and information.