Why is my attempt at downloading Big Sur failing? I am currently using a MacBook Pro 13&quot; Mid 2018 with Touch Bar.
Today macOS Big Sur was released and I tried to download it but it's getting stuck at 484.4 MB. Initially, it shows 16-17 minutes left, but as soon as it reaches 484.4 MB it's stuck and the timer goes till 10 hours!
My Wi-Fi is totally stable with a speed of 100 Mbps.
I tried to restart my Mac but it still gets stuck.
Earlier there were similar issues in the App Store (even now they are). The issue was I was not able to download an app unless I connect to the US VPN. I even contacted support but they were not able to help out. It wasn't a big deal as a VPN could be used.
But now even with VPN, it gets stuck.
Apple servers had a documented outage to the software updates.

https://www.apple.com/support/systemstatus/


This is why failures happened globally on November 12 during the launch day of Big Sur installations.

https://support.apple.com/en-us/HT201475 How to upgrade to macOS Big Sur

If you are having issues on or after Friday, November 13 and there isn’t an outage listed in the status page above, and step 4 above doesn’t work follow these steps:

Close system preferences
Quit any apps that cause internet usage (All web browsers, streaming or games, etc...)
Open the Mac App Store and find Big Sur

More details are here on recent changes to this weeks releases - https://eclecticlight.co/2020/11/13/still-getting-errors-trying-to-upgrade-to-big-sur/
If you’ve done anything odd like clearing caches or run tools like Onyx, I recommend you do a safe boot to let Apple clean up properly, then run this command from your terminal.
softwareupdate --fetch-full-installer

If you get any errors, don't worry - wait 5 minutes and try again. (Especially errors about SUPreferenceManager: Failed to set object of class - those do not prevent downloading the latest full installer)