Update to macOS Big Sur 11.1 from 11.0.1 fails

Another possible solution is to disable your security software if you have any. I got the error three times and then disabled my Kaspersky security on the fourth go. It then successfully downloaded and I'm about to reboot to install.

This may avoid the hassle of having to restart in safe mode.

Apologies if this gets posted twice.

I followed the safe mode advice and it worked for me. (Late 2015 build desktop 27")

I did not remove my external drive and yes it did seem to stick at the 10 mins mark but worked in the end.

Seems "Apple Minutes" are 'Approximately Equal' to "IBM Minutes"

If you have an external drive mounted try ejecting it before starting the upgrade. Do this in safe mode.

thanks . i chatted with apple support and we did a SMC reset then i got it installed OK but it took 5.5 hours

I was getting this error and safe mode didn’t help. It turns out I didn’t have enough disk space available.

Try the Safe Mode install.

Hey There, So I read in an Apple Developer Forum from user BenHaith that if you download Big Sur from the App Store it should work! It took a while but was able to install the new software update. Hope this helps!

Safe mode did the trick. Thanks!

I've tried to download that a couple of times also, unfortunately with the same error message either 'download failed' or 'installation failed'. It hasn't yet completed the download.

What is most frustrating is that I can download the whole 3.27 gig update file (where does it go!) yet when it get to processing it for installation the 'download failed' error occurs - even though it's already completed the download. I've done this 4 times now, trying different solutions including safe mode. It won't pick up from a downloaded file and starts from zero each download.

Yesterday all my desktop icons disappeared, I have a sneaky suspicion this is something to do with iCloud credentials or certificates. The log files show "The connection to ACDAccountStore was invalidated"....

I have the same issue. Cannot update in normal mode using software update or App Store download. File downloads to computer, then while “preparing macOS bugsir 11.1 update” it fails saying a problem with the internet connection. Same exact behavior in Safe Mode.

Called into Apple support and they suggested doing a format/reinstall as the only option.

I have tried all of the above and all have either stuck on installing or installation failed. Think I will have to wait until the next update; sense it’s an update bug ( 2015 MacBook Air)

I also tried Safe Mode. Did't work. Then I tried the app store option suggested by roger137. It takes longer, but it works. I now have 11.1 running on my Mac Mini. Thanks!

Boot into Safe Mode by booting with the Shift key held down and try the update from there.

NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following; =

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

Identical issue on the same configuration. 4th time downloading a 3.27GB file...only for it to fail due to the internet connection (which is fine), even after the file has fully downloaded and is 'preparing'.