Recovering from Time Machine getting error

[Scoobie Newbie]

Good day. I was running Big Sur, decided to do a recovery from a previous save and I get this message: Unrecoverable error. SecurityAgent was unable to create requested mechanism builtin login. The drive was wiped in order to do a recovery. Any help would be appreciated.

 

[IWT]

Firstly, a warm welcome to Mac-Forums and thank you for your post.

What does "decided to do a recovery from a previous save" actually mean? Are you talking about Time Machine backup? Or a cloned backup? Or something completely different?

So: recovery from what?

We weren't there sitting beside you as you set up all these things. Bear with us and take us through the whole process from start to finish, please.

Ian

 

[Scoobie Newbie]

sorry. It was a time machine back up. Computer off. Drive plugged in. Computer started. Control R (I think, recovery mode). Computer does it’s thing. Asks me from which saved point do I want to choose. I pick the most recent which was 10 days ago. It then says it’s copying files. After a couple hours the screen goes black then the Apple logo appears then I get that error message.

 

[chscag]

Recovering Big Sur is more difficult when employing the same recovery process that was used on previous versions of macOS. The reason is that Big Sur implements a measure of security that in effect encrypts the system drive.

It does appear though that you erased the drive prior to recovery and restoring with Time Machine. I'm not sure if that was necessary. You might have to do a clean install of Big Sur 11.2.1 first and then try restoring with Time Machine.

 

[Scoobie Newbie]

How do I do a clean install?

 

[Scoobie Newbie]

Not sure if it helps but my wife has a MacBook with OS X El Capitan.

 

[MacInWin]

Here you go: https://support.apple.com/en-us/HT204904

 

[Scoobie Newbie]

Awesome. Hope this works. I guess I’m going with macOS Catalina

 

[Scoobie Newbie]

So tried that. Got the following: MacOS could not be installed on your computer. This source contains a newer release of macOS. Your Mac requires an upgrade before you can migrate from this source. Quit the installer to restart your computer and try again.
I click restart. Then eventually get Unrecoverable error. SecurityAgent was unable to create requested mechanism built in prelogin

 

[Scoobie Newbie]

i Can open up disk utility and it tells me 11.32 GB Used and 358.31 GB other volumes. 130.44 GB free

 

[chscag]

So tried that. Got the following: MacOS could not be installed on your computer. This source contains a newer release of macOS.

Sounds like you did not properly wipe the drive clean. The Big Sur recovery partition may still be intact and the installer sees that and will not overwrite with Catalina.

 

[Scoobie Newbie]

So am I supposed to go into utilities and erase the drive?

 

[MacInWin]

Yes, at the device level. In disk Utility click on the "View" button and select "Show All Devices." Thel select the hardware device and repartition. This action will erase the entire drive. Use APFS and GUID and it will create a Container and then Volumes inside that Container. Here is a screenshot of what I mean. WARNING: Doing this will erase everything on the drive completely, so make sure you have your files stored somewhere safe.

 

[Scoobie Newbie]

Will this make it impossible to use the recovery option from this link? https://support.apple.com/en-us/HT204904

 

[Scoobie Newbie]

This is what I have. So if I understand repartition the Apple SSD using APFS and GUID?

 

[MacInWin]

This is what I have. So if I understand repartition the Apple SSD using APFS and GUID?

Yes, and yes, it will delete the recovery partition. But the Internet Recovery will still work, as will installing from a bootable USB drive with the installer properly installed on it. But this is what you have to do to go back from Big Sur to any older version.

 

[Scoobie Newbie]

Ok. Seems to have worked. I am backing up with this OS. I do have all my stuff saved from Time Machine from earlier in the month. What should I do to get everything back to normal without the headache?

 

[Scoobie Newbie]

So my stuff is till there. How do I access it?

 

[Scoobie Newbie]

Tried to upgrade from Catalina to my Big Sur. Getting the same error. FML

 

[Scoobie Newbie]

Anyone?