Видео ютуба по тегу Django Python : Manager Isn't Accessible Via Model Instances

Understanding Django's Manager Error:
Understanding Django's Manager Error: "Manager isn't accessible via username_and_password instances"
Django Python: Understanding the Manager's Accessibility via Model Instances
Django Python: Understanding the Manager's Accessibility via Model Instances
Django : AttributeError: Manager isn't accessible via Section instances
Django : AttributeError: Manager isn't accessible via Section instances
Django : Django
Django : Django "Manager isn't accessible via UserProfile instances"