My El Capitan comes up on "System Administrator" user

Please read this whole message before doing anything.

This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.

Step 1

The purpose of this step is to determine whether the problem is localized to your user account.

Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

Test while logged in as Guest. Same problem?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Step 2

The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.

Please take this step regardless of the results of Step 1.

Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.

Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem?

After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of Steps 1 and 2.

You're logging in as root. Does your regular account appear in the Users & Groups preference pane? If it does, please select it and then right-click or control-click the name in the account list. Select Advanced Options in the popup menu. In the sheet that opens, what is the User ID?

I need to be absolutely sure I understand your response. Are you looking at the user ID of the "System Administrator" account, or of another account with a different name?

A

I think you mean that this particular account is not "System Administrator." If I'm right about that, change the user ID to 501, or else to the smallest number that is larger than that and not the user ID of any other account. So for example, if other accounts have the user ID's 501 and 503, you would use 502. Make sure you don't give the same ID to two different accounts.

After you have done that, see below.

B

Start up in Recovery mode. When the OS X Utilities screen appears, select

Utilities ▹ Terminal

from the menu bar. A Terminal window will open. In that window, type this:

resetp

Press the tab key. The partial command you typed will automatically be completed to this:

resetpassword

Press return. A Reset Password window will open. You’re not going to reset a password.

Select your startup volume ("Macintosh HD," unless you gave it a different name) if not already selected.

Select your username from the menu labeled Select the user account if not already selected.

Under Reset Home Directory Permissions and ACLs, click the Reset button.

Select

 ▹ Restart

from the menu bar.

C

Follow the instructions in this support article under the heading "Disable the root user." You must authenticate in Directory Utility as "root" with the password you used to log in as System Administrator. Authenticating as another administrator won't work.

If you use FileVault, you first have to launch Disk Utility from the main Recovery screen and unlock the startup volume.

Please restart the computer in safe mode. Certain caches maintained by the system will be rebuilt.

Safe mode is much slower to start up than normal. The next normal startup may also be somewhat slow.

When the login screen appears, restart as usual (not in safe mode) and test. There's no need to log in while in safe mode.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t start in safe mode. In that case, ask for instructions.

What backups do you have?

That's adequate only if you're willing to lose 10 days' worth of work. Are you?