macOS Big Sur 11.2 update download failed error

Same problem. Retried several times. Why they don't retain the download cache so we don't have to re-download the entire 3.25GB from the beginning each time is beyond me. The problem is NOT the internet connection. All the "solutions" I've seen so far on this forum are work-arounds (hacks). Apple needs to fix this ASAP. It took me several attempts and a lot of freeing up of disk space to get Big Sur to install in the first place. Now the thing can't even update itself, despite my MBP having plenty of free space. I don't want to reboot into safe mode, stand on one foot, pat my head and rub my belly. I want an updater that A) works or B) at least provides accurate error messages. If I'm going to pay more for a product, I expect it to work at least as well as the competition.

eelko208 wrote:

Also, I do not have a download in my Downloads folder (~/Downloads). Do not remember seeing a download there for any previous system updates either.

System install packages are not download to the Downloads folder. They are downloaded and run from the Applications folder. So look in there to see if there's a Install macOS Big Sur.app file in there. If there is delete it.

Then boot into Safe Mode according to Start up your Mac in safe mode - Apple Support , go to the App Store search for and download Big Sur. Then run the installer while still in Safe Mode:

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

Hello Tigrosso,

Thank you for using Apple Support Communities!

We understand from your post that after clearing space on your laptop you are still unable to update the software due to an error saying that the download failed. Look for an installer in the downloads folder and put it in the trash. Then try downloading the update again. If the issue persists, try reinstalling the current software using macOS Recovery and then downloading the update again.

How to reinstall macOS - Apple Support

Best Regards.

It appears that the error is misleading. Several people have reported the same issue, including me after unsuccessfully tried everything Apple support had to offer (sans reinstall) like different networks, disk repairing, safe mode.

https://discussions.apple.com/docs/DOC-250003367 Read right to the End and within that posting is a Link to Best Defense from Malware etc

Without getting long winded - on these Forums AV Software is considered as ^%$ware and that is based on Very Very Long experience of myself and those even longer on the Apple Eco-System. Viruses do not exist for macOS, yes Malware does but only if people purposely download or do not do due Diligence on where they get their Software

David_MofU wrote:

Issue Resolved: I have Kaspersky Internet Protection as my AntiVirus/etc.

First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

Also, unless you're using a true VPN tunnel, such as between you and your employer's or bank's servers, they are useless from a privacy standpoint: Public VPN's are anything but private.  

For what it's worth a while back the government banned Kaspersky software from it's computers as it was to insecure. That and the fact that it's worthless for Macs is good reason to uninstall it.

As I said, I have already upgraded to Big Sur (which involved at least 10 separate 12+gb downloads!). I am trying to install one of the frequent updates to Big Sur (which has now involved a similar number of 2+gb downloads). Does the same hack work for updates? This seems pretty silly, frankly. In any case, each time I attempt to update, whether in safe mode or not, the download completes and then freezes with a message that 10 minutes remain. I have left it in that state, with the fan on constantly, over night. Also, one process is usually pegged at high CPU usage. I can't afford the time or bandwidth to do this again right now, but here's a screenshot of the beginning of the name of the process (com.apple.MobileSoftwareUpdate...)

The error message in picture explains everything - Internet Connection is either not working or is too unstable / slow to download the update reliably. Suggest restarting the Wifi Router and then restarting the laptop in Safe Mode - immediately hold Shift Key at restart. Disconnect all other devices using the Wifi - this will give the max bandwidth to laptop. Once logged in the computer will function slower - Normal. Try the download again.

It is not the Wifi, the message is misleading.

I tried to install several times in the past few days. Get this message every time, Wifi is working fine everywhere else. Tried with a cable connection instead of Wifi, same result.

Also, I do not have a download in my Downloads folder (~/Downloads). Do not remember seeing a download there for any previous system updates either.

Well one more way might be to reboot in Recovery Mode - Command + r - keys immediately at startup and connected via Ethernet. Presented with various option >> choose Reinstall macOS. This time, it was download the Full Installer 12.18 GB and attempt the installation. Some call this an In-place Installation. It should upgrade 11.1 to 11.2.

Strongly suggest doing a Time Machine Backup Before attempting and if doable - create a Bootable Clone to external drive as Insurance

I've been having the same problem since updating to Big Sur. Each update has been difficult, with multiple fails. And it's happened to three other Macbooks in the house. I second the thought that there should be a method of downloading once rather than re-downloading the same file over and over again. Moreover, once for the entire household would be even better. What a waste, especially for people on limited connections. In any case, I've tried everything except re-installing and would prefer not to lose the day it will take to do so. This is a pretty offensive suggestion for a $2trillion company: "If the issue persists, try reinstalling the current software using macOS Recovery and then downloading the update again." Waste your time, not ours! Have a good day! Seriously. Fix your software.

Suggest - restart Router and then Shutdown Computer and connect via Ethernet connection. Restart computer in Safe Mode - Shift - Key immediately at startup. It does a Repair Disk, clears cache files and load only Apple Software - load slowly - Normal. Once in Open Apple Apps Store and find Big Sur and download. Try not to let computer go to sleep mode or Screen Save to activate. Be patient as one knows it Big Sur is 12.18 GB size. There are often periods where it seems to pause the download , normal be patient as countdown clock may say 15 minutes but in Real Time could be 30 - 45 minutes. This can and will happen several time in the process. If all goes well. it will successfully download and attempt to Launch. Do NOT allow it to start - Quist the Installer. Check Applications Folder for new App called Install Bug Sur. Make a copy to External Drive - future usage. Now, restart again in Safe Mode - then launch the Installer.

If this is not to ones liking and as last resort - Boot Safe Mode - Shift - Immediately and Open Terminal. Copy and paste this command  " softwareupdate -l " without quotation marks. This should List all available updates. Now, still in Terminal copy and paste this command again with quotation marks " softwareupdate -1 -a " - what was listed in previous command will start the download and attempt to install.

Those using this ^&*ware are somewhat misguided. macOS is not Windoze environment. Carrying that idea over to macOS is a big mistake. As many persons, on this thread, may have AV, Disk Cleaners etc installed - even disabling said stuff and still having issues installing the Big Sur update tends to prove the point just how invasive and disruptive this is.

The advise offered to intending to assist. The User always has the choice to accept it or disregard it.

It's not about personal preference. Advices like this (uninstall a whole category of programs _plus_ VPNs) along with the whole restart your system, boot in safe mode etc are what programmers call Shotgun Debugging. There are logs in every system that can help understand the problem (I had it too without having installed any of the "cursed" software mentioned - only thing worked was a recovery reinstall) so Apple Support _had_ to ask for those logs... but they didn't.

I have the same problem with a 1 ½ year old iMac 21.5 in Retina with 3.6 GH i3 and 16 GB ram and 1T hard drive when I tried to update to both 11.2.2 and 11.2.3. And yes I turned off my Norton anti-virus and same message pops up after the update has already been downloaded and it is ¾ of the way through the installation. Reminds me of a Windows 7 update that permanently rendered 10's of 1000's of machines unable to ever do an update again: had to bin it and buy a new windows machine with that one. Come-on Apple give your customers the support they deserve: they are paying your salaries after all. Please fix this Big Sur garbage and don't abandon us.