Lost user account after OS update
Recover lost user after update.
Sometime we found that user account suddenly disappears without a trace from the system leaving only "Other accounts" option available, but the user folder is still present from external OS / Single user mode.
One way is to recover the user account is to re-create the user by forcing MacOS to re-do the setup process.
To do this, boot up to Single user mode (cmd + s)
- mount -uw /
- ls -l /Users (take a note of the user account name and who the permission belongs to (staff:501 or staff:user)
- rm /var/db/.AppleSetupDone
- exit (will continue to load the OS) / Reboot (will reboot the system)
Now you should be greeted with the Apple Welcome screen, and be able to setup the user.
Follow trough the setup, and re-create the user account.
If all goes well, you get the everything back just as it was.
This process by default only works if the UID of the user was 501. If the lost user's UID is different, you may loose permission to the User's home folder, so you will have to edit it from the advanced user settings to match it (Check the UID from terminal by typing ls -l /Users)