this mac can't be used to migrate data

Please CAREFULLY read the following:

When you buy a new Mac the easiest, quickest and most reliable method is to simply connect the old Mac's Time Machine External Hard Disk to the new Mac using a USB cable before you turn on the new Mac. When you start the new Mac for the first time it will startup Setup Assistant (SA), SA will get to a point where it asks if you are migrating from another computer, select Yes  and follow the on-screen prompts and it's done! It is THAT simple.

If you have already done SA on the new computer then simply connect the Time Machine External Hard Disk using a USB cable and launch Migration Assistant (MA) which is located in Applications - Utilities - MA. Then follow the on-screen prompts. 

The ONLY difference between MA and SA is MA will create a new user account that you need to log into.

Both SA and MA migrate applications (not 32 bit apps) , data files, settings, it does not migrate Mac OS itself. Some professional apps such as Adobe and Microsoft apps may require re-installing their apps as they will not allow them to be migrated. As long as you kept the security keys for installing their apps, it is not a big deal. 

Had the same issue. Turns out it was because the user account I started it from didn't have a password set.

The correct method to migrate is to connect the old Mac’s Time Machine drive using a USB cable to the new Mac and then launch Migration Assistant. Works every time!!!!!

Hmmm, it "works every time."

Riddle me this -- what then, when you've had Macs for almost 20 years, have always been able to successfully transfer and then all of a sudden cannot?

I received my M1 MBP a few weeks ago and have struggled to migrate all my data. At first, I was able to use Migration Assistant to boot from my old MBP Time Machine without incident. The issue was that not all the data transferred and neither did the licenses on my specialty software. After days of fiddling with it, I decide to do a clean sweep of BOTH devices. Reinstall the OS and run a brand new Time Machine backup on both.

This morning, I attempted to use Migration Assistant on the new M1 MBP using the new/old Time Machine backup of the old MBP and I got this message: "This Mac can't be used to migrate data. Due to an issue unlocking this system, you can't migrate. Please update this Mac and retry."

I have no idea what is causing this issue. Do you have any suggestions on how to resolve? Screenshot because you seem to not believe people when they say they cannot migrate successfully.

Hi, I don't know if you've fixed your issue; but after hours of searching for a solution, I found this and it worked for me so I thought I'd share. https://support.apple.com/guide/apple-configurator-2/revive-or-restore-a-mac-with-apple-silicon-apdd5f3c75ad/mac Good luck.

Edit: It does say this process is for silicon M1, but Apple Configurator 2 works for any type of direct connect revival. If you have another healthy Mac handy, the general process should work.

I'm having exact the same issue. Once the first time this message appears, after it I cannot get the Migration Assistant to work. Every time I get the same message, even when connecting a clone hard drive from the old Mac or connect both via USB cable. It appears that it doesn't even look to the drive, but the Mac is locked somehow!

Is there anything else I can do??

I am a problem solver. I like to work things out for myself, be self sufficient. That is what this Apple Community forum is for -- to help empower ourselves to find the answers to our questions and/or ask someone more knowledgeable.

The point of my comment was to indicate that software, because developed by humans, is not infallible --- it is impossible to say that something works every time. I spent about 13 hours wiping and hard resetting this M1, including time on phone and chat with 4 different senior Apple advisors and no one had an answer for this bricked M1 and the types of issues I was having. I did, eventually, find a solution which worked well -- at around 2am EST.

[Edited by Moderator]

I have this same issue on my brand new MBP. Connected both Macs with cable, opened migration assistant on new MBP, check from a mac and get: "This Mac can't be used to migrate data. Due to an issue with unlocking this system, you can't migrate. Please update this Mac and retry"

Hi ramireaj,

Some of the new M1 Macs shipped with macOS Big Sur 11.0. Apple has acknowledged that this version is faulty, and that such Macs should be updated to Big Sur 11.0.1 or later.

These steps might be helpful to fixing the issue: If you get a personalization error when reinstalling macOS on your Mac with Apple M1 chip - Apple Support

Yes, you should be in contact with AppleCare to see if they have any solutions for your problem. If you have not been in touch with them is there a specific reason you haven't?

Please try Apple's steps as described in Revive or restore a Mac with Apple silicon with Apple Configurator 2

This fixed my issue!