How can I revert/downgrade to macOS 15.1 from 15.2?

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Level 1

9 points

How can I revert/downgrade to macOS 15.1 from 15.2?

macOS 15.2 has broken some of my software. I want to revert to 15.1. I have a TM backup and I booted into system recovery to try to restore the previous version from an earlier date. It won't do it. It wants to reinstall macOS (I presume 15.2) and then use migration assistant. This is obviously not what I want. Does anyone know if there is a workaround to restore my TM backup ? And why system recovery won't restore a previous version?

Also might I have better luck erasing the disk and then trying a TM restore?

TIA

[Re-Titled by Moderator]

Mac mini (M1, 2020)

Posted on Dec 17, 2024 11:19 PM

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Answer 1

Top-ranking reply

Barney-15E

Level 10

121,988 points

Dec 18, 2024 12:31 AM in response to Escaladieu

TM no longer backs up the OS, just your data. You would need to download a 15.1 full installer, if it exists. Then, create a bootable USB installer from that. Boot from the USB installer, erase the drive, install macOS, then migrate from a TM backup made when you were running 15.1.

To see if there is a full installer, in Terminal use

softwareupdate --list-full-installers

If It is available,

softwareupdate --fetch-full-installer --full-installer-version 15.1

Create a bootable installer for macOS - Apple Support

If you attempt to migrate from a backup made with 15.2, it will want to reinstall 15.2 before migrating.

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Answer 2

Dec 18, 2024 3:08 AM in response to Escaladieu

OK I was where you are. Build a 15.1 boot USB. Boot from that (hold option key on boot). Erase the hard drive. Install 15.1. Start migration assistant. Worked flawlessly for me. GOOD LUCK.

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Answer 3

Escaladieu Author

Level 1

9 points

Dec 18, 2024 12:59 AM in response to Barney-15E

That's helpful, thanks

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Answer 4

Escaladieu Author

Level 1

9 points

Dec 18, 2024 8:10 AM in response to SkySkiFlipper

Thanks, I got it done.

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