Time Machine Error: "An error occurred while erasing your restore destination disk. Try erasing the disk with a Disk Utility or choosing a different disk to restore to.” - Attempting to downgrade Monterey to Mojave.
This is less a question and more a solution to an agonising process I just went through trying to restore my MacBook Pro 2016.
There was a number of roadblocks and dizzying amount of obstacles on the way so I’m going to try summarise best I can.
What I did chronologically and what happened:
- Wasn’t happy with the performance related to the recent Monterey upgrade and was wanting to downgrade back to Mojave. I thought a simple reboot from Time Machine would fix it but I was sadly mistaken.
- Time machine couldn’t get past the “preparing to restore stage”.
- I then, wiped the whole hard drive, OS and data. Same problem ensured. Now including: “An error occurred while erasing your restore destination disk. Try erasing the disk with a Disk Utility or choosing a different disk to restore to,” when trying again to restore.
- Thanks to “MuzeTiK” from here (https://discussions.apple.com/thread/253487912) for identifying the problem:
“this issue comes from a version conflict between the macOS recovery firmwares”.
- The solution (for those wanting to downgrade):
You NEED to make sure that the backed up Time Machine OS version, matches that with which you are restoring to.
I.e you cannot have a current operating system of Monterey and restore a Mojave Time Machine backup.
It needs to be like and like.
- So now I was stuck with a computer with no OS
- Two Options:
OPTION 1
- If your shipped with OS matches your Time Machine backup and your stuck on the “preparing to backup” stage, follow MuzeTiks solution: macbook stuck on preparing to restore mac… - Apple Community
How to know your shipped with OS?
- Shut down your computer
Turn back on holding Cmd + shift + option + R this will take you the your shippingOS.
If that matches your Time Machine backed up OS you’re good to go. Follow MuzeTiks solution ^
Mine didn’t match (my shipped with OS was Sierra and I needed to get Mojave back)
So onto ….
OPTION 2
- If your shipping OS doesn’t match the OS of your time machine’s backup OS you need to follow this guide: Trying to revert to Mojave from Monterey - Apple Community
Specifically (as mentioned in the guide above):
- Download that specific OS that matches the one on your Time Machine
- create a bootable usb (Create a bootable installer – Apple Support (AU)
- reload your hard drive with that OS
- THEN restore your Time Machine backup
E.g.
In my case I had no OS(I wiped it) AND Time Machine wouldn’t restore so:
- Enter recovery mode: cmd + R
- Reinstall Monterrey via internet restore.
- Once restored, download Mojave (from the AppStore) and create a bootable drive (Create a bootable installer – Apple Support (AU))
- Turn off. Re-enter recovery mode.
- Plug Mojave bootable usb drive in
- Wipe hard drive again. Go to Disk Utility —> click the View button (in the uppermost toolbar) —> "Show All Devices." —> click the very first drive available in the top left, should say “Apple APFS Media” —> Erase. Make sure Format: APFS and Scheme: Guid Partition Map). Name it Macintosh HD
- Come back out to main screen
- install MojaveOS
THEN FINALLY
- Turn off, turn on again in recovery mode. Restore from Time Machine Backup.
- Remember like for like as we said.
I hope this helps and was explained ok. The clown show at Apple were clueless on how to help.