An error occurred preparing the software update - Big Sur

I assume you made the usb drive correctly using the createmedia command in terminal?

All USB drives are formatted as fat32 for Windows but they don’t come with a windows OS. When you enter the createmedia commend in terminal, it will ask if you want to format the usb drive which will erase everything on it in order to install Big Sur and format it for Mac. You’ll type y for yes and it will say formatting 1% 20% 40% etc.

It can take a while for it to boot off of though.

Hope that helps.

after "sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume"

is there anything else need to be done?

I forced eject it and put it on the dead Macbook, see the Big Sur installer, but that really takes a long time without any progress bar or indication anything is happening.. So I wiped the USB3.0 flash and try to make the installer again. 

Will see if that would help.

Thanks for the quick reply. I wish there was a way such as a live chat where where I could help you more in real time. If you are on Twitter I believe they have a DM feature.

I had to made a usb stick today of Big Sur so will get back to you first thing tomorrow morning with the exact command I used to create my own drive successfully

Hope this helps and we’ll be in touch.

Hi Sacha

Yes it works, I eventually resolved to call apple support to finish the installation and had an amazing patient senior technician who helped through the final steps. What is the problem you are facing now ? I’ll see if I can help.

after i turn it on...

there ws a disk image written : "mac OS installer"

and connect to wifi.

after I did this the normal home page comes where I log in and after the progress bar is hal,f the apple logo on the black screen comes up with a progress bar showing the time remaining.

did it happen with you? or you were able to login from the home page? because I dont know how to backup laptop in this condition? Please help

Hi AshleyDii..

Could you please help me wth this?

after i turn it on...

there ws a disk image written : "mac OS installer"

and connect to wifi.

after I did this the normal home page comes where I log in and after the progress bar is hal,f the apple logo on the black screen comes up with a progress bar showing the time remaining.

did it happen with you? or you were able to login from the home page? because I dont know how to backup laptop in this condition? Please help

Hi Soren Pearson, I am facing the same issue with Macbook Air 2017 and have tried restarting it again and entering the password for the startup disc which does not accept the correct password. I haven't backed up my data on the time machine and do not remember any encryption password for FileVault. Please help...

Hi Fred, do you manage to install using a USB stick?

With USB stick and I select the Big Sur installer, it still lead me to the MacOS recovery mode, and as always my password would not work so it becomes a dead loop.

Yes guys..... do not update to big sur PLS!!!

i had the same issue: macbook asking for your password to your account but the password not working, my macintosh HD password didn’t even work and eventually it would not even show up anymore.

I was on the phone with Apple Support for 4 hours and they could not help me.

we tried everything: Command R, Shift option command R to get to the macOS Recovery, but i had no backup with TimeMachine, disk utility didn’t help...

even tried to use an USB stick to download El Capitan on it and sort of transfer it or something and tried to use ‘resetpassword’ in Terminal but no...

my internal harddrive was not found even though with Command R you could see that my account was still there.

When in El Capitan on the USB, it was showing as if the internal harddrive was completely empty.

i ended up just having to use command shift option R to use ‘reinstall OS X’ which led me to OS X El Capitan again (now without the USB)... with zero of my old files. I started blank and without all my photos/files for uni, everything.

just don’t update to big sur pls.

(i also believe this error occurred bc of the low storage i had but i’ve heard a lot of issues with the update in general)

Catalina or Mojave is fine really, so pls don’t take this risk like we did bc i for sure lost everything.

the most stressful day ever.

Hi,

It should have caught it, but in my case, it didn’t. And I could perfectly install the Big Sur to the external HDD and later to my deleted, totally empty Mac. I was only able to go back into my operating system when the phase I have mentioned first happened: when the software had been installed to the external HDD. Before that, I couldn’t. I could not log into the computer. Of course not only a lack of space but a damage on the disk could occur. Although it seemed to me that the lack of space was the problem, since I only had like 9G free space on my Mac and it wasn’t caught early enough by the installer. Anyways, with the help of the two external HDDs, I could solve it.

Thank you for asking.

Hi Soren,

Hoping you can help! I’ve experienced the same issue as everyone else (no time machine backup, unable to proceed any further with the big sur update).

I have created a bootable installer of Catalina, I go to install it by holding option when turning the computer on and I am unable to select the Catalina USB bootable drive as it says that the drive is “locked”. I followed the apple instructions correctly and the USB is formatted correctly for Mac.

Not sure where to proceed from here! As mentioned, I don’t have a backup and can’t risk losing my data.

Can anyone explain the process of using another Mac to be a target device?

Thank you!

Hi,

I brought mine to a 3rd party to help reinstall the OS and they looked at it and said along with the space issue, my firmware was out of date and that is why I had a mess with my machine. Losing my data, but that’s ok.

450 aed for the update and reinstall.

Wish you all much luck

thanks,

Hey, I had exact same problem when i was trying to update the mac os to Big sur. I tried your suggestion and press Option and then turn on the computer. i end up having a sign of circle with a line in it.

any more suggestions?

Thanks

I'm glad you did not erase, because I have a workable solution for you!

https://mrmacintosh.com/big-sur-upgrade-not-enough-hd-space-serious-issue-possible-data-loss/

I feel bad for others that have been caught up in this issue for the past 3 months. So many bad experiences leading to complete data loss. It took quite some time to piece together what was going on here, even more to work out a fix for the problem!

HI Brian

i have exactly same problem.

can you tell me how to create MacOS Mojave usbkey installer as you said,

then how to you install to an external drive?

Do i need to format the USB Mac OS Extended ?

Thank you