title: django.core.exceptions.ImproperlyConfigured: AUTH_USER_MODEL refers to model 'player.Player' that has not been installed
body: <p>I couldn't find any solution, that's why I must make a new thread here.
  The app <em>player</em> is of course installed and I didn't forget about putting <strong>AUTH_USER_MODEL = 'player.Player'</strong> in <em>settings.py</em>.</p>
  
  <p>Obviously I tried to delete DB and migrations and it didn't work neither.</p>
  
  <p><em>models.py</em> code based on tutorial made by CodingWithMitch below:</p>
  
  <pre class="lang-py prettyprint-override"><code>from django.db import models
  from django.contrib.auth import get_user_model
  from django.contrib.auth.models import AbstractBaseUser, BaseUserManager
  
  User = get_user_model()
  
  
  class MyPlayerManager(BaseUserManager):
  
      def create_user(self, email, username, password=None):
          if not email:
              raise ValueError('Users must have an e-mail address')
          if not username:
              raise ValueError('Users must have a username')
  
          user = self.model(
              email=self.normalize_email(email),
              username=username,
          )
  
          user.set_password(password)
          user.save(using=self._db)
  
          return user
  
      def create_superuser(self, email, username, password):
          user = self.create_user(
              email=self.normalize_email(email),
              username=username,
              password=password,
          )
  
          user.is_admin = True
          user.is_staff = True
          user.is_superuser = True
          user.save(using=self._db)
  
          return user
  
  
  class Player(AbstractBaseUser):
      # USER FIELDS
      email = models.EmailField(
          verbose_name='email',
          max_length=100,
          unique=True,
      )
      username = models.CharField(max_length=50, unique=True)
      date_joined = models.DateTimeField(
          verbose_name='date joined',
          auto_now_add=True,
      )
      last_login = models.DateTimeField(verbose_name='last login', auto_now=True)
      is_admin = models.BooleanField(default=False)
      is_active = models.BooleanField(default=True)
      is_staff = models.BooleanField(default=False)
      is_superuser = models.BooleanField(default=False)
  
  
      USERNAME_FIELD = 'username'
      REQUIRED_FIELDS = ['email', ]
  
      objects = MyPlayerManager()
  
  
      def __str__(self):
          return self.username
  
      def has_perm(self, perm, obj=None):
          return self.is_admin
  
      def has_module_perms(self, app_label):
          return True
  </code></pre>
  
  <p><strong>@Edit</strong>:</p>
  
  <p><em>settings.py</em> code below</p>
  
  <pre class="lang-py prettyprint-override"><code>INSTALLED_APPS = [
      'django.contrib.admin',
      'django.contrib.auth',
      'django.contrib.contenttypes',
      'django.contrib.sessions',
      'django.contrib.messages',
      'django.contrib.staticfiles',
  
      'player',
      # some other apps
  ]
  
  AUTH_USER_MODEL = 'player.Player'
  </code></pre>