an error occurred applying the software update

Here's the fix: External. Plug in your MBP/MBA SSD via External Adapter, and install Big Sur from a USB Bootable.

I had a client with a Early 2015 MBA and her issue was the same. She went to the apple store prior, and they installed a new SSD temporarily and got Big Sur to work, so they told her she needed a new SSD, because the Genius Bar wasn't able to get Big Sur to work on her current 500GB SSD, only Catalina. I ran into the same issues no matter what I tried. The issue is the internal SSD becomes Unmounted during the installation process, most likely from the installer package, and doesn't Remount.

The solution that worked for me was to plug her SSD into an external adapter, and then load Big Sur that way. I also tried a 2012 MBA SSD via External Adapter on her 2015 MBA and Big Sur installed perfect as well.

Seems like when it's plugged in externally it's not having that dismount problem.

Thank you. This helped me. I did a disk utility on all the volumes before re-attempting the Big Sur download and install.

Same error happened to me 💔

Also, I'm a graduated student and really need Apple support to help us ASAP please 💔

I don't want to erase everything because I have my projects and reports for the college and no copy for them 💔

Please help us.

It seems that things are worse for me. I can start in Mac OS recovery and I can see my user account but password doesn’t work. If I try to access by using Apple ID same thing: my password doesn’t work. If I boot in safe mode and try to access the network, once again the password doesn’t work. I’m sure passwords are right. Any idea?

This seems to be working for me, it looks like my MAC dropped my Wi-Fi connection during the update to Big Sur and I got the error popup. I followed your instructions and was able to reconnect my wifi (had to plug in a keyboard and mouse as obviously Bluetooth wasn’t available) I’ve restarted the update. So far seems to be updating. Thank you for your input.

Hello nisha291. Sorry to hear about your problem. Not fun. I can only suggest taking your computer into an Apple store and see if they can help. Usually software issues are fixed free of charge. Clearly they are many people,e having issues and they are not all being addressed. I think they would be able to get around the password as well. They will set it up as a new computer. That is what they did for me. Took under 45 minutes. Best of luck. I hope you find a solution. Be well.

I had to take it to Apple. They wanted 99 to erase and bring restore. I had no back up.

I took it to my church and the geniuses there and they erased it and restored it for free. I got advice on how to back up in the future. Free.

I think this is why some updates don’t do a thing to bring positive change. Sorry if not more helpful but it is honest. Apple doesn’t love you after your purchases are made.

If you went into Recovery disk, connected to the internet, didn't you have access to the Disk Utility?

What computer and was it operating properly before you tried to upgrade to OS 11?

Same issue. No colume to recover in MacOS Recovery as well. Donno how to do now

My Macbook air (2018) model was running properly with latest MacOS Catalina.

I tried MacOS recovery but cannot reachthe disk utility screen. No users on this volume to recover......

same problem and now stuck on recovery page with all the option but unable to select anything as screen stuck. Any suggestions?

Do you have time machine backup before upgrade?

Finally I need apple support to reset my Macbook Air and I restore my files from time machine backup.

I had the frozen cursor too. It wasn’t until I got into the menu to reinstall that it went away. But yes, I had it over and over until I got into the utility menu.

Same thing happened to me. After being on the phone for 2 hours with support the only option left was to erase everything and reinstall Mac. It loaded Mohave back, I tried Big Sur again and the same thing happened. 🤦🏻‍♂️

If you can boot to the recovery mode then you have access to Disk Utility.

Not accepting yur password for the User probably means either it is trying to access a different drive/user or the User got corrupted (an old problem not seen much anymore).

When Recovery mode comes up, if I remember correctly, you see a screen with a language choice then you proceed to the next screen which could be an installer or choice screen.

At the top of the window you will have a menu bar, in the rightmost menu you have access to some tools, like Disk Utility, Terminal and such.

Run Disk Utility, see what drives list on the left side. Choose your start up drive and then run Disk First Aid on it.

Also, if things fail to resolve but you are in the Recovery mode then you will have access to use the Time Machine backup drive.

I d hope it is a separate drive.

Again, when I resolved my wife's iMac problem I was able to boot holding the Option key down and saw the drives list on the scfreen.