MacOS Big Sur get stuck on 12.18 GB of 12.18GB

It's 3p ET on Tuesday, and every now and then I click upgrade and then wait a few minutes till we reach 12.18 and .... fail. Bet I've tried 50 times over the past few days on my 2018 Mac mini and my 2018 MacBook Pro . It's low impact, since everything is working fine, but still.

Did you try connected to a different network or using a vpn?

I have no idea how Apple has cocked this one up so bad, but the one and only thing that worked for me was a network change. Never had any trouble with this before, and don’t have any weird router settings or anything.

connecting to a vpn was a lot easier than trying to putz around figuring out which setting in my Google Wifi system Apple didn’t like.

download first stuck at 12.18, then at 7.56. tried this fix and it worked. according to progress bar, download started from the beginning but proceeded very rapidly until it was well advanced, then bogged down and finished very slowly. left it running and found it showing restart screen with 'about 10 min remaining.' that went normally until 'less than a minute remaining.' that minute took approximately forever, but the computer seems to be working now.

thanks, hamiltonfrommaputo.

I've tried this fix probably 10 times. Every time I attempt to stop the download process and then restart it, it still says 12.18gb and the download bar looks identical.

I have not gotten the update to install yet, and I've been working on this for hours (exercise in futility I know and I've been doing other things too, but still...) - Apple PLEASE get this fixed.

I had the same problem. Do you have a firewall/av software that checks downloaded files in a sandbox? Disabling the sandbox on firewall fixed my problem immediately. I hope that helps someone else. This tip would have saved me a lot of time :-)

After many many weeks I used the above steps with no hope at all. Surprisingly it finished download and is installing as I'm writing. I think the trick here is to randomly interrupt the progress by disconnecting internet.

I finally got around the install issues by creating a second admin user (and down grading the original admin) then doing the download and install overnight. Seems that all the issues I had with the Catalina upgrade (iMac 21.5 late 2015 fixed 8gb RAM) went away when I upgraded to Big Sur. Now the issue is that I can't get rid of the original user. System Preferences hangs up when I try to delete the user. Just a pain the butt when I login accidentally with the original user as my iMac hangs up trying to optimize.

Well done my friend. I just had the same problem upgrading from Catalina to Big Sir, and it stopped at 12.12GB. I set my internet connection to inactive, then back to active and I was able to resume my download. :)

I ran into the same thing except mine stuck at 12.20 when trying to update from Mojave to Big Sur. Tried all sorts of methods, to no avail. Finally relented and used “clean my Mac x” to clean up the Mac, which I feared may have a virus on it. The cleaning seemed to work. Re-attempted the update, which got hung up at 12.20 for about 2 minutes, then finally busted through and got to the installation window. May have been a glitch on Apple’s part, but at least I now know there is no malware on my Mac. Also, the update must be large, as it takes quite a while to install, esp over WiFi.

I saw a video that you can download updates from here https://support.apple.com/downloads/macos however, apple hasn't added Big Sur to the list.

Mine is stuck at 12.20, not even moving a bit

Just wait it out. It takes a while.

Update: Tried it for the 5th time today and it just worked all of a sudden. It’s currently doing more stuff so it could still go wrong. If I remember, I’ll message this thread about the result

Mine would always start over the download from 0 what can I do?

Same with me, I'm using MacBook Pro Retina, 13-inch, Early 2015. Been waiting for days now.