Migrating your files and folders from an old Mac to a new one is not that hard.
Unless you get stuck with the Authentication Failed message.
Apple’s Migration Assistant app makes moving your stuff over to a newer Mac easy. But if you’re getting this error message when trying to move everything over. It’s so frustrating and time consuming.
Below you’ll find. Some of our favorite cures for Migration Assistant not working authentication failed.
Fixes that’ll help you out.
Migrating from your old Mac to a new Mac. And getting the ‘authentication failed” message in Migration Assistant?
Or even migrating from a PC using Windows Migration Assistant.
It’s highly likely it is your new Mac that’s causing this issue. The Mac you’re running Migration Assistant on.
Fix : Reset the System Management Controller (SMC).
This is the quickest fix. And it sorts out most of the authentication failed messages. And even better it’s quick to do.
New MacBook’s with the T2 security chip.
Do the following on a Mac with a T2 chip (these chips enable) touch id.
And if you have touch id on your M1 Mac, MacBook Pro or MacBook Air. Then you’ve one with the T2 chip in it.
You can also check by. Logging into your Mac. Click on the Apple symbol (top left corner of your desktop screen). And from the Apple menu that come up choose About this Mac.
Click on System Report from that screen. And from the list that comes up click on controller. And it should say if you’ve a T2 security chip in your Mac.
To reset the SMC.
1. Shutdown your Mac.
Wait until it’s fully shutdown. And this means waiting at least 10 seconds after everything switches off.
2. Then hold down your Shift key + Control key + Option key. All at the same time for 7 seconds. Keep holding those keys and once the 7 seconds have passed. Then also press hold your power key.
5. You’ll know you’ve got it right if your Mac powers off as you’re holding the keys.
6. Then keep holding all 4 keys for another 7 seconds.
Count down the seconds. As it’s important to properly wait the right amount of time to reset your SMC.
7. Wait a few seconds more. Then press the power key to power on your Mac.
If your Mac is a Desktop Computer
As well as shutting down your Mac. Take the power cord out. Wait 15 seconds before putting your power cord back in again. Wait another 5 seconds then press the power key to switch back on.
For MacBook Pro’s and MacBooks Without the T2 Chip
1. Switch off and shutdown your Mac.
2. Hold down your Shift key + Control key + Option key. And while holding these keys down you hold your power button. Keep all four keys down for 10 seconds.
4. Then power on your Mac.
You can also look at this Apple document here. On how to reset the SMC of your Mac computer.
5. After you’ve Reset the SMC on your Mac.
Log into your Mac. And retry your data migration. Your Authentication Failed message should have gone.
Fix: Authentication Failed Message On Migrating From A Time Machine Backup
Can You See Your External Drive on your Desktop?
Does your external drive with your Time Machine backup on it. Come up on your new Mac’s desktop?
When you plug in your external drive before you open Migration Assistant. It’ll look something like this.
If your Mac can’t see it. Then you’ll get an authentication failed message. First check that your new Mac’s desktop is set up to show external drives on the desktop.
You do this by opening up a Finder window.
Then go into your Finder window preferences.
Then click the option to show external disk on the general tab.
And your external drive with your Time Machine backup on it. Will come up on your new Mac’s desktop.
At that point you know for sure your new Mac can see the external drive.
If it doesn’t come up then there’s likely something physically wrong. Or the USB port software is somehow hung.
Double Check Your USB Cable To And From Your External Drive Works
Try your USB cable and adaptor if you’re using one. On your old Mac or another Mac. Do they work there?
Because USB cables can suddenly break and fail. It’s always worth double checking.
Check Your Old Mac Can See Your Time Machine Backup Drive
You’ve likely just taken a backup of your older Mac. But if you’ve not used your backup drive for a while.
Plug it into your old Mac. Can your old computer see its backup drive? Does it try to take a backup to it?
It’s best to have the latest copy of your files and folders. Before you migrate with Migration Assistant.
Resetting Your New Mac’s USB Ports Often Helps
You do this by Ejecting your external drive first. Then plug out your USB cables. Then shutdown and restart your new Mac. A full Shutdown rather than a Restart is often needed.
You could try a Restart first. But I’m betting you’ll end up with a full Shutdown. Wait a few seconds for everything to stop. Then power on.
Assuming you’ve set your Finder preferences to show External disks on the desktop. Once you’ve logged in. Then plug in your external drive.
It should now be up on your new Mac’s desktop. And once your new Mac can see your Time Machine backup drive.
Your Migration Assistant app not working because of an authentication failed error should be gone.
Fix: Start From Scratch On Your New Mac.
Yes, I know this sounds an extreme fix for an Authentication Failed error.
But bear with me while I outline the reasons to go this route. And you’ve tried everything else suggested in this article.
Sometimes Setup Assistant just didn’t get it right the first time. Or somehow the initial set up of your Mac at the factory just didn’t go quite right. And you just need to start your Mac from the beginning.
When your new Mac has nothing but MacOS on it, then you’ve little to lose but some time by trying this. And you might have to do this to sort your authentication failed issue out.
You restart your new Mac from zero by:
1. Boot your Mac to MacOS Recovery Mode.
On an Apple Silicon based Mac. You do this by pressing and holding down your power button until you see the start up Option screen. Click the Icon with Options on it.
Or On an Intel based Mac, power on your Mac and straight away hold down the command key while pressing the letter R.
2. Type in your administrator account user name and put in the user password.
After that you’ll be at the MacOS Recovery mode screen.
3. Click on the Disk Utility option.
It’s best to first try this. Just to see where your Mac’s internal drive is up to.
Go into Disk Utility and then pick First Aid. To run a check on your Mac’s internal drive.
Just to make sure that there is nothing up with the drive. And if there is Disk Utility will repair. And remove any bad sectors.
If First Aid says it can’t find your internal drive. Then you’ve no choice. You for sure have an unhappy Mac. And you’ve little choice but to reformat your internal drive to start from scratch. Disk Utility calls it Erase.
Assuming you haven’t had to Erase your new Mac’s internal drive. And First Aid ran fine. You may at that point choose to restart your Mac. Log in and try your data migration again and see if that has sorted out your issue.
You’re back to booting to MacOS Recovery. And at this point it’s worth plugging your Mac into a power outlet. And making sure your new Mac is on your WIFI and the Internet. As you’ll need access to download MacOS.
4. Pick to Reinstall MacOS from the menu.
Choose your Macintosh HD if you’re asked.
5. After your MacOS installation has finished.
And this should take around an hour to do.
Allow your Mac to restart. And go through Setup Assistant again.
This Apple article here has some more info about reinstalling MacOS in case you need it.
After your Mac has reached the log in prompt. Put in your user account name and password to log in.
Open Migration assistant and restart your Migration.
Migration Assistant is a powerful tool that can help you transfer your data from one Mac to another.
But just sometimes you’ll get the authentication failed message.
Now you’ve some cures for your Migration Assistant not working Authentication failed error.
If this post didn’t answer all of your questions why not take a look at the related articles below.
About Paul Gregory
I’ve been a system administrator for various corporates for 15 years. And as admin I’ve helped many with their Mac’s and there many Apple devices.
I’m excited by watching users, armed with a little knowledge take control of their Mac’s and their files. And why not?
When I’m not at work or working on the site I like to chill with few beers. And watch a bit of car racing. From Formula 1 to stock car racing. The competition is my thing.