Downgrade Sonoma to Ventura with Time Machine, but need Migration Assitant

Question

Downgrade Sonoma to Ventura with Time Machine, but need Migration Assitant

I'm on a 5 year old iMac (Intel) and want to downgrade to Ventura. I use Time Machine and have bacups with Sonoma and earlier backups with Ventura. Several sites say it's easy: restart in Recovery Mode, choose Time Machine, etc. It all worked well until the last step. It says I need Migration Assistant installed to complete the process. WTF? So... do I simply download and install Migration Assitant and then go through the entire process again? No source I've found mentioned this problem when using the "easy" downgrading method with a Time Machine backup. Any advice would be much appreciated?

iMac 27″, macOS 14.4

Posted on Apr 27, 2024 3:49 AM

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Answer 1

PRP_53

Level 10

85,147 points

Apr 27, 2024 5:52 AM in response to John Macdonald2

John Macdonald2 wrote:

A follow up. . . I see I already have Migration Assistant in the Applications Utilities folder. So it looks like it's not going to work as advertised. And I'm not nearly computer savvy enough to created a bootable disc. Am I stuck with Sonoma, in which everything processes at the speed of a crippled snail?

https://discussions.apple.com/content/attachment/164b11a8-fcb1-4034-bb85-50d907985323

Clicking "Install macOS" simply takes me back to the Recovery utilities screen.

Predicated on the User byline " iMac 27″, macOS 14.4 "

This appears to an Apple Intel Computer ?

Time Machine sadly does not contain a full and working copy of the Operating System

That stop somewhere around macOS 11 Big Sur

TM Backup does contain all this was in the User Folder ( Home Folder ) of this computers

To Downgrade is possible but will require creating a Bootable Installer of the previous version of macOS

I suggest a a Bootable Installer as it is better to have the Operating System Media on bootable installer disk rather than deepening on Internet Recovery Mode

Scorched Earth Method

This method will WIPE ALL Data and there is No DATA Recovery - Period.

>> Only works on Intel Based Apple Computer <<

To perform this action will require booting from a Bootable Installer.

The Bootable Installer can Only be performed on an Apple Computer

This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer. Example : Bootable Installer of Big Sur would have to be done on a computer that Qualifies to run Big Sur.

Notation: If the computer being used to perform this action is Too New or Too Old to qualify to run the version of macOS - this computer can’t be used.

Alternative is, to gain access to a Qualifying Apple Computer from a family member, friend or associate.

Shutdown computer and disconnect all external drive Except the newly created Bootable Installer.

Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive.

It will present options >> Disk Utilities >> View >> View ALL attached Drives.

Choose the Upper Most Drive ( not the volumes indented and list below ).

The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. This applies to macOS 10.14 Mojave and above.

Once that is done >> backup out of Disk Utilities and choose install macOS.

Follow the prompts and it may automatically reboot several time.

Upon a final reboot - Setup Assist will present with the newer version of macOS.

You can use Setup Asset and point it to the Time Machine Backup Drive. This is a One Time offer. Thereafter you will need to use Migration Assist

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Answer 2

Apr 27, 2024 8:07 AM in response to PRP_53

Thank you, PRP. I appreciate your explanation - it wasn't my inability to understand instructions.

It's unfortunate the outdated information (that TM doesn't contain a full, bootable OS) is still being included among suggestions for downgrading from Sonoma to Ventura via Time Machine. Evidently, it simply can't be done using Time Machine. I'll go the bootable installer route.

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Answer 3

PRP_53

Level 10

85,147 points

Apr 28, 2024 7:46 AM in response to John Macdonald2

No bugging.

You have an honest question so ask away 😀

Would use the Backup from Ventura

Then of you what to bring back Personal Documents which are more recent ( Sonoma period ) bring them back via Time Machine Restore the Deleted Files

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Answer 4

Apr 27, 2024 4:11 AM in response to John Macdonald2

A follow up. . . I see I already have Migration Assistant in the Applications Utilities folder. So it looks like it's not going to work as advertised. And I'm not nearly computer savvy enough to created a bootable disc. Am I stuck with Sonoma, in which everything processes at the speed of a crippled snail?

Clicking "Install macOS" simply takes me back to the Recovery utilities screen.

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Answer 5

PRP_53

Level 10

85,147 points

Apr 27, 2024 8:33 AM in response to John Macdonald2

John Macdonald2 wrote:

Thank you, PRP. I appreciate your explanation - it wasn't my inability to understand instructions.

It's unfortunate the outdated information (that TM doesn't contain a full, bootable OS) is still being included among suggestions for downgrading from Sonoma to Ventura via Time Machine. Evidently, it simply can't be done using Time Machine. I'll go the bootable installer route.

Unfortunately it is so 😩

It seems Apple may have placed too much faith in users already knowing this was so.

Not everyone spends long hours on their computers doing Technical Stuff and do have a life outside these ASC Forums

If you run into issue on this adventure or have additional questions

Do ask before proceeding rather than afterwards

Good luck

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Answer 6

Apr 27, 2024 11:07 AM in response to PRP_53

Thank you again, PRP_53. I've read several suggestions on downgrading to Ventura using a bootable USB and watched two youtube videos - all are essentially making the same suggestions. So long as I follow the steps carefully, it seems doable.

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Answer 7

Apr 28, 2024 7:33 AM in response to PRP_53

I hope I"m not bugging you but you're clearly very knowledgeable about this. I was successful in creating a bootable installer for Ventura on a USB. I understand the restart, holding Option key, choosing the installer, etc. It's after I've successfully erased the hard drive and installed Ventura that I'm confused. After installation, Migration Assistant will book and I'll plug in my Time Machine backups. I have both a backup from yesterday (all documents and files up to date) when I was running Sonoma. I also have a backup from 3 weeks ago when I was last running Ventura. Should I choose the most recent backup or the one when I was using Ventura (and then manually update the files)? I"m concerned about any apps (like Photoshop) that may have automatically updated to Sonoma but now wouldn't run because of my going back to Ventura. Thanks so much for any advice!

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Answer 8

Apr 28, 2024 9:29 AM in response to PRP_53

Shoot. In my excitement that everything was working and impatience to keep things moving, I chose the most recent backup I made, with Sonoma. But it still has hours to go and I can cancel the transfer and start it again, if you think it’s that important. If we’re a serious mistake, I would have expected to have read a warning on the forums I used for research. Many thanks!

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Answer 9

PRP_53

Level 10

85,147 points

Apr 28, 2024 9:37 AM in response to John Macdonald2

One issue that may occur.

The actual pictures in Sonoma >> Photos application may not render correctly in Ventura

Some might occur are music files in the Music Application when downgrading back to Ventura

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Answer 10

Apr 28, 2024 5:33 PM in response to PRP_53

Once again, you were absolutely correct, PRP. The clean reinstall of Ventura worked perfectly. But after using Time Machine and Migration Assistant to reload all the data from the latest Time Machine backup (when I was using Sonoma) rather than going to an earlier back when I was using Ventura, prevent me from opening iMusic - the music library wouldn't load, having been created with Sonoma. But I simply replaced the new music library file with an early version from Time Machine and it now works perfectly. Lastly, when I open the Photos app, it automatically restored the photos. So I'm back with all files preserved and running Ventura. Can't thank you enough for your kindness and help and willingness to share your expertise.

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