500 internal server error when updating macOS

The MacBookAir7,2 code is assigned to MacBook Air 13” early 2015 and to MacBook Air 13” 2017.

If you should have an add-on VPN client apps, add-on anti-malware apps, add-on anti-virus apps, or add-on cleaner apps around, those can interfere with communications and updates.

Either disable and remove those apps and reboot, or boot into Safe Mode (which disables most of those), and try again.

500 is an internal error from a remote server. The question with some of the above apps is whether that error is arising locally, from some other server involved in your communications, or is a server is at Apple. Add-on VPN clients intercepting traffic would not surprise.

It’s also quite possible that the Apple servers just “lost the plan” for a bit, and retrying the request will succeed.

As pervious poster outlined and resolve these issue first.

Have seen a few other experiencing similar issue Error 500 and may suggest as last resort to use the method below and choose Big Sir to install.

Be very sure of having enough Empty Space of at least 36 - 50 GB empty Space or Big Sur will fail and fail again and again.

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.

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.

I had same problem, please see my post https://discussions.apple.com/thread/252913639?answerId=255496827022#255496827022