Big Sur download error

Hi there!

Are you able to download apps or app updates from the Mac App Store? This error usually means there's an issue connecting to the App Store.

If you haven’t already, please be sure you have 44.5GB of available storage on your Mac.  

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Try the steps here: If you can't connect to the App Store, iTunes Store, or other Apple services

Then, follow these steps for upgrading to Big Sur: How to upgrade to macOS Big Sur

The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

macOS Big Sur is compatible with these computers. If this computer Qualifies - Yes it can upgrade to Big Sur. If Not Qualified - proceed to below and choose another version of macOS that it does Qualify to run.

With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install. Make sure to use Only Safari to commence the download as Other may not work

Make a Time Machine Backup Before attempting. Notation - Mojave is the Last version to support 32 bit applications / extensions and Drivers. Catalina and Big Sur Only support 64 bit and there is no workaround.

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.