Inaccessible user account on Macbook

Hello guys, so I have this MacBook Air 11" (Early 2015) in my lab and the main user account is completely inaccessible.

Here's what happens: you input the password, the wheel starts turning and it never stops. After many minutes the password input interface reappears and it's a loop.

Now, I'm not a Mac expert, mostly because here in Italy they're very rare, so I get less than 10 of them a year. But I've always been able to fix them.

This time I've tried all the usual stuff: boot in safe mode, repair system drive, reset PRAM and the like.

Nothing seems to work. I have the option of making a clean reinstall, but the customer would like to recover her files first.

I usually remove the drive and insert it into a PC able to read Mac formatted drives, but this time it's an M.2 drive with proprietary connector and I have no adapter right now.

So can anybody suggest anything more? Thanks guys.
Daniele BrunengoIT Consultant, Web DesignerAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Andy MIT Systems ManagerCommented:
Have you tried using the Mac OS boot CD to reset/remove the user account password? Could be an issue with the password itself. Alternatively does the boot CD allow you to create a new admin account and then log into that and take control of the files in question to back them up?

Alternatively you could try booting to a Linux disti (should be able to download a Linux based live-cd like Ubuntu for free) and use that to access and copy the files over to a USB drive before wiping.
Daniele BrunengoIT Consultant, Web DesignerAuthor Commented:
I don't have a Mac OS boot CD right now, but I like the Ubuntu suggestion. I'll try that first.
Daniele BrunengoIT Consultant, Web DesignerAuthor Commented:
I've tried that, but Ubuntu won't even recognize the Mac file system.
Determine the Perfect Price for Your IT Services

Do you wonder if your IT business is truly profitable or if you should raise your prices? Learn how to calculate your overhead burden with our free interactive tool and use it to determine the right price for your IT services. Download your free eBook now!

Tim LapinComputer Consultant (Desktop analyst)Commented:
A few questions first:

1)  Which version of the O/S is on the Mac?  (General question here but it might have an impact on the solution)
2)  Are there other accounts and if so, is at least one an Admin level account?
3)  Is the main user's account an Admin level account?
4)  Can you get into single user mode?

I have some ideas but I need to know the answers to the above first.
Daniele BrunengoIT Consultant, Web DesignerAuthor Commented:
1) It should be Sierra or High Sierra.
2) There is only a guest account
3) Yes
4) I didn't try that, I will right away
Daniele BrunengoIT Consultant, Web DesignerAuthor Commented:
Yes, single user Mode works.
Tim LapinComputer Consultant (Desktop analyst)Commented:
Once in as Single User, you can reset passwords, mount file systems and so on.  Examples can be found here:

To copy files, you need to mount the appropriate file system and then use the standard UNIX command cp (copy).  Here are some examples:

If you have another Mac at your disposal, you can try to mount the problem Mac in what is known as "Target Disk Mode".  The hard drive mounts as a data disk, allowing you to copy files.

Similarly, one can use the Recovery option to invoke Time Machine, if the resources for it are available.

At the very least, once the files are copied, the drive can be wiped (again via the Recovery boot menu) and a fresh copy of everything installed.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Daniele BrunengoIT Consultant, Web DesignerAuthor Commented:
I don't think they even know what Time Machine is.
I followed all the steps for Single User Mode, as detailed in the second link.
I mounted the usb key (exfat) and copied all the files from the user's folders (like /Users/Username/Desktop) but I only found empty folders copied, each containing a single empty file named .localized

Is there any chance there are permission problems using this method? I don't know, it only managed to copy some files from the Library folder, all useless.
David AndersTechnician Commented:
The Recovery Partition can be used to change a user's password. (done this several times)
Also can setup an administrator account (have not done this option)
Tim LapinComputer Consultant (Desktop analyst)Commented:
Look at the detailed view of each directory, for example the user's Documents directory.  What are the listed permissions?

Use the ls -alF command to see the permissions details.  Then post them here if needed.

You might have to leave remove the "p" flag on the copy command.  That flag preserves various parameters, including the Access Control List settings.  Instead, just do a "cp -r".  That might be the fix.
If it's High Sierra, then you may not be able to read the drive yet, unless you have another High Sierra system.

When you boot into single user mode, you have to manually mount the disk (mount -uw /) to fully operate on it.  If it's mounted and not showing.

Install OS X onto a USB disk and boot from that.  Then see if you can read the M.2 from the external disk.
Daniele BrunengoIT Consultant, Web DesignerAuthor Commented:
Tim's first suggestion actually worked.
The user folder they told me to look into was wrong, probably a remnant of a deleted user.
The right folder contained all the files and I was able to save them.
Thanks a lot, this will be hugely useful in the future too.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Apple Hardware

From novice to tech pro — start learning today.