migration assistant shows "authentication failed"

Resetting the SMC worked for me... and only had to do the first procedure. See instructions here: https://support.apple.com/en-us/HT201295

I had this same issue while migrating from another Mac (both Big Sur). The Mac I was migrating data to was the culprit for me. Resetting the SMC on it as instructed here: https://support.apple.com/en-us/HT201295 did the trick.

I was able to resolve by resetting the system management controller (SMC) Depending on your version the instructions can be found here: https://support.apple.com/en-us/HT201295

For my new Macbook Pro with Intel chip, I turned off the computer then pressed command + option + shift then pressed the power button and held all 4 buttons for 10 seconds. Then turned my computer back on and all was resolved. Best of luck!

I had troubles and connected the machines by USB cords. It still did not work but after I took them off, it worked for no apparent reason. I guess keep trying is the answer. I looked here in case it was a Big Sur glitch. Seems like it is not.

I'm having this issue. Beyond irritating. Setting up a new iMac, wanting to migrate from previous (2014) iMac, did the following:

1) Got old iMac up to date with latest Big Sur.

2) Switched on new iMac, logged in with Apple ID, hooked the two iMacs together via ethernet, attempted Migration Assistant -- it said old iMac was running newer OS so I'd have to update.

3) Updated to latest Big Sur on new iMac. Waited ages while it downloaded and installed. It seemed to do this twice.

4) Attempted to use Migration Assistant again. Now it fails saying it's failed to retrieve authentication etc etc. Don't understand it - it knows who I am!

5) Tried restarting, switching off and removing power cord, etc etc. Same deal.

6) Tried recovery mode. Tried to reinstall Big Sur. It asks for a password to unlock the HDD. Every time I enter it, it just ignores me.

Help!?

I was able to resolve by resetting the system management controller (SMC) Depending on your version the instructions can be found here: https://support.apple.com/en-us/HT201295

For my new Macbook Pro with Intel chip, I turned off the computer then pressed command + option + shift then pressed the power button and held all 4 buttons for 10 seconds. Then turned my computer back on and all was resolved. Best of luck!

This worked for me too! Thank you!

This help with SMC reset to do my migration assistant from my time machine. Thank you.

I bit the bullet and called Apple on the phone. I only had an 7minute hold so that was nice, relatively speaking.

• The tech had me go into recovery mode (hold down Command+R during boot) and then had me run disk utilities.
• We tried first aid on my main drive and it didn't work for me. The computer kept saying that the disk didn't exist.
• She finally just made me... reformat the drive! Thank God this is a new computer otherwise I'd be freaking out about backing up all my files.
• We reinstalled macOS Big Sur. It took about 40 minutes to install. Everything worked fine after that.

Hopefully you don't have to reinstall the OS but at least this is an option if all else fails for you.

Hope that helps!

-Angel

Oh my, I also have this question. The only difference with mine is that I'm trying to migrate from and old (2015) MacBook Pro to a new (2020) MacBook Pro. Both MacOS are on the same operating system as well (BigSur).

I eagerly await a response from anyone who can help.

A solution: I ejected all USB devices, shut down the machine, plugged the USBs back in, restarted. The external drives now showed up on the desktop (for the first time, this is a new machine), and Migration Assistant worked.

I this is a password problem. Set my password on new mac, then was going to add new users; couldn't unlock add new user using the same password that I just set. On to the solution, go to the recovery console (boot with command-R); run the security program from the toolbar. set and store your password. Optional things I did: allow your system to reboot other systems, e.g. allow booting a USB drive). Anyway, was able to run MA after this process.

Hi,

I’m so sorry that this is going on for you. I messed with that same issue for like two hours before I finally broke down and called their customer service.

I called 1-800-MY-APPLE and only waited about 6minutes before getting help (I know “only”) haha. But compared to the holds I’ve been having daily, 6minutes felt fast. The woman on the phone seemed to have a few extra tricks up her sleeve.

If you do call and get them to fix your issue, please let us know what you found out.

I hope this helps,

-Angel

Thanks everyone. The computer was trying to make me look like an idiot (not too difficult) -- resetting the SMC chip (as per Cweb285's post) seemed to do the trick. Just needed to leave it unplugged for longer! In the end it worked seamlessly. Hope this helps anyone with a similar issue.

Yep, me too. I've just bought a new iMac, running Big Sur, and I can't restore from Time Machine. Keep getting this authentication failed, can't validate credentials (or whatever the wording is).