How can I regain admin rights on Sonoma 14.2.1 without reinstalling?

Hutch76 wrote:

It's strange - as I have tried to log in but don't have the password.

If the current macOS you are logged into is not an "admin", then your only option is to attempt to reset the password of the other user account using the instructions in the following Apple article:

If you forgot your Mac login password - Apple Support

If you cannot do so, then you will need to start over with a clean install which involves first erasing the disk (or rather deleting the "Volume Group") followed by reinstalling macOS & restoring from a backup.

This has been my Mac for 4 years and I have never set up a second user account. I set the mac up from scratch. Any idea how this could have happened?

Or perhaps you restored from a Time Machine backup. Depending how you restore the backup, if TM sees you already have a particular user name on the system, you will be presented with an option to remove the current user or to rename the user account that is being restored (I think that is correct, I know you get an option to rename one of the accounts).

However, as @Barney-15E mentions.....your screenshot looks exactly like what happens when a user attempts to rename their user account & does so incorrectly (very common). When initially creating a macOS user account, the installer will take the Long Name you provided and remove the spaces for the Short Name. For example during initial setup if you provided the Long Name "Steve Jobs", then the short user name would become "stevejobs". That seems to be the case with the second user shown in your screenshot "markhutchens". The first user account with all the red circles on the folders is one where the short user name "mark" was customized either during the initial setup, or later on when someone tried to change it which would have resulted in exactly what we see in your screenshot.

If you Log Out, is there another user available? Can you log into that with any known password?

If so, does it have admin capability?

If so, you could use it to give the other user admin capability.

Can you do this in Sonoma? I was worried about trying it:

No. It's at the bottom of this article: What's new for enterprise in macOS Sonoma - Apple Support

It's always been a security deficiency and now it is blocked.

—Reboot macOS into "Single-User mode" by holding down Command-S

There isn't a single user mode anymore. Equivalent is using Terminal in Recovery, but that won't help in Sonoma.

— Remove the file controlling whether the setup process is run by typing:

rm /var/db/.AppleSetupDone

It's not there on Sonoma (or any of the macOS versions where the System and Data volumes are separate).

Did you relocate the home user folder by any chance? I know that some macOS updates in the past (especially with Monterey) would break the custom setup where the home user folder was relocated to another drive.

Hutch76 wrote:

I think my only option is to erase and do a clean install. I have no idea where the second user came from and as it is a 'Standard' user I can't give that user admin rights without an administrator account.

Did you try resetting the password of the other user account just in case it may be an admin user account?

If I migrate my TM backup after the erase and new os install, will I have admin rights?

Hard to say. Normally it would be a yes, but since we don't know when or how this occurred, nobody can say until you try it.

Or will do I set up a new admin account on the new os before I do the migration?

That would probably be a good idea. I would recommend using a name other than the two shown in your screenshot so you don't have to worry about deleting it or renaming a user account. Having a spare admin user account can be helpful if something happens to the main admin user account.

I can tell you that even if you have two admin user accounts, you may find when trying to authenticate to the security enclave chip that only one of the two admin user accounts may be shown so make sure not to forget the password for either account. I have no idea why only one user account appears sometimes when trying to authenticate with the security enclave chip when booting into other modes or when you need to "Activate" the Mac after a DFU firmware Revive. I have seen it happen on both Intel T2 Macs & M-series Macs.

Sorry - When I bought the mac I just used the migration assistant and I can't remember the process.

Understandable.

Here are some things to try:

Restoring Lost Administrator - Apple Community

Unless you have another admin user account on that system, there is nothing you can do except to start over since the old trick to have macOS run Setup Assistant again to create new admin user account does not work in Sonoma.

I set the mac up from scratch. Any idea how this could have happened?

No. As has been alluded, it usually occurs when someone tries to change their short user name or tries to move their home folder without using another admin user account to make the changes.

I haven't heard of it happening out of the blue.