I would like to remove a user account under El Capitan by following this recipe:
- Choose Apple menu > System Preferences, then click Users & Groups.
- Click the lock icon to unlock it, then enter an administrator name and password.
- Select the user you want to delete, then click Remove below the list of users.
What happens is that I cannot select the to-be-deleted user at this point (I can only select the current account plus "Guest User"). What could be wrong. (And yes, I am using an account with administrator privileges.)