Unable to upgrade to macOS Big Sur 11.6

Hey there!

How is the available storage on your Mac?

Otherwise, have you restarted to try again?

Another way to test, or even to get the job done would be to:

Startup in Safe Mode and try again, (May prevent other software from interfering):

https://support.apple.com/guide/mac-help/start-up-your-mac-in-safe-mode-mh21245/mac

Even creating another admin account in System Preferences > Users and Groups, log into that user to do the update.

https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac

Another suggestion would be to either:

Try another network, or:

Disconnect your router from power for a minute, plug it in again, and try again.

You can also, however, (Depending on your Mac model, startup in internet recovery, (While holding Command Option R) > Reinstall the OS, (This would install the latest available OS version, for Intel Macs though).

https://support.apple.com/guide/mac-help/use-macos-recovery-on-an-intel-based-mac-mchl338cf9a8/mac

Hope one of those helps!

Check if there is Enough Empty Disk Space. Yes, like the initial upgrade from previous version of macOS to Big Sur had empty space requirements >> to a lesser degree the same principle applies for the update thought not as much space is needed. Should that not be the issue for your computer >>

If this update is for Big Sur 11.6 the error message can be misleading. There are factors like poor Wifi connection, slow wifi connection, too many other people downloading at the same time and Apple Severs are overloaded.

Software on the computer interfering with the download process including AntiVirus software, running behind a VPN.

If via wifi too many Other devices using the wifi at the same time reducing the Bandwidth to your computer.

Best Results are via Ethernet Cable to Router

There are several ways to download the Big Sur 11.6 update. 

1 - Connect to Router via Ethernet connection and restart the computer in Safe Mode and then open the Apple Apps Store and get the Full Installer of Big Sur. It will be the 11.6 version and once downloaded run the installer from the Applications folder.

2 - Restart the computer in Recovery Mode ( INTEL Command + r ) and choose Reinstall macOS. It too will download the full Installer and commence the installation. For M1 CPU the Recovery Mode is Here

3 - This method may seem unnecessary but sometimes the Router Restart clears Network issues from ISP to Apple Servers

Shutdown Router. Shutdown computer and disconnect all External Drives. Restart Router. Connect to Router via Ethernet Cable. If via Wifi - Disconnect all other Devices using the Wifi - want the Maximum Bandwidth only for this computer. Restart computer in  Safe Mode. It does a Repair Disk, Clear System Cache files and only load Apple Software, extensions and Fonts. Will load slowly - Normal. Once Logged in - open Apple Apps Store and  Get the Full Version of Big Sur. It will take some time and several pauses will occur - normal. Countdown clock may say 15 minutes but in Real time may be 30 minutes. Same goes for clock at 10 minutes could be 20 minutes in Real time. Eventually , Full Installer will download and a New Application in Applications Folder will present called Install Big Sur. Stop there and perform a Time Machine Backup. If desired - have an External Drive - Copy & Paste the Install Big Sur Application to external drive for future usage - making a Bootable Installer. Now run the Installer.

Have found this method more reliable than the Software Update which is very iffy at best

Are there any AntiVirus, Disk Cleaner, Optimizers, Defrag, VPNs etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation.

Experiencing the exact same issue. I am on macOS Big Sur Ver 11.4 iMac Retina 5k 27 inch, late 2014

I have the same problem with 11.6 update as this person does

I have tried this over and over three times and my internet connection is perfect.

I've experienced the same issue after trying to download upgrade 11.6 several times.

I have exactly the same issue. I am trying to ugrade form Big Sur 11.3.1 to Big Sur 11.6 and keep getting the same message about the internet. Is there a solution?

Hi there!

Others may have a more direct solution, but I did post some steps to try above if you’d like to give them a try, I’ve personally used all of them in the past to fix similar issues, cheers.