MacBook Air 2020 upgrade to Sequoia 15.7 fails

Startup in Safe Mode and Update.

Start up your Mac in safe mode - Apple Support

If that doesn't get you updated to macOS 15.7 Sequoia.

see > If an error occurred while updating or installing macOS - Apple Support

+1

Given the MS software that is installed and running on your Mac.

I also suspect that you have installed some third-party AV-ware, Protection-ware or a VPN that is causing an issue.

EtreCheckPro is an excellent tool for locating issues induced by third-party software.

Download and run the free version of EtreCheckPro, from > https://etrecheck.com/en/index.html

Then post back here with your Report, as per > How to use the Add Text Feature When Post… - Apple Community

Wazmack wrote:

What's the latest OS upgrade I can go to for my 13-inch, 2020, MacBook Air. Currently running Sonoma 14.5 but when I try to upgrade to latest Sequoia 15.7 it faills to install? Cheers

[Re-Titled by Moderator]

Original Title: MacOS

Exactly, what is the Error Message that is presented when attempting to upGrade to macOS 15 Sequoia

The answer might be included in the error message

➡️ MBA compatible with macOS 14 Sonoma ⬅️

• MacBook Air (15-inch, M3, 2024)
• MacBook Air (13-inch, M3, 2024)
• MacBook Air (15-inch, M2, 2023)
• MacBook Air (M2, 2022)
• MacBook Air (M1, 2020)
• MacBook Air (Retina, 13-inch, 2020)
• MacBook Air (Retina, 13-inch, 2019)
• MacBook Air (Retina, 13-inch, 2018)

➡️ MBA compatible with macOS 15 Sequoia ⬅️

MacBook Air

Identify your MacBook Air

• MacBook Air (15-inch, M4, 2025)
• MacBook Air (13-inch, M4, 2025)
• MacBook Air (15-inch, M3, 2024)
• MacBook Air (13-inch, M3, 2024)
• MacBook Air (15-inch, M2, 2023)
• MacBook Air (M2, 2022)
• MacBook Air (M1, 2020)
• MacBook Air (Retina, 13-inch, 2020)

Thank you

I really suggest following the advise from my colleague @den.thed 👍 especially the second link regarding " If an error etc "

Just to add an addition suggestion if nothing else works ( last resort )

There are factors:

Some which are beyond your control and those which are totally under your control

Like poor Wifi connection

Slow wifi connection

Too many other people downloading at the same time and Apple  Servers are overloaded

Software on the computer interfering with the download process including AntiVirus Software

Notation: Disabling the AV Software may or may not solve the issue.

Removal of the AV Software may increase the chances of the download to perform as expected.

Running behind a VPN which may increase Packet losses or corruption of the download 

Turn Off any Third Party Two Way Firewall and try again 

If via wifi  & too many Other devices using the wifi at the same time reducing the Bandwidth to your computer. 

Best Results are via Ethernet Cable to Router

Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal 

Try Again using the Software Update Applet in System Preferences / Setting 

Worst case - Restart in Recovery Mode and choose Reinstall macOS. 

This in theory will pull the latest version of macOS this computer qualifies to run 

++ 1

🦉

If I may say

Your success is our success

To give credit where credit is due

This was a co-effort between @den.thed and self 🦉-53

I'm glad to hear that the issue is resolved. Thanks for the update.

It sounds like Safe Mode disabled the third-party ware that was blocking the update.