Model class django.contrib.contenttypes.models.ContentType doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS
<p>Whenever I try to run makemigrations or runserver, I get this error:</p>

<pre><code>RuntimeError: Model class django.contrib.contenttypes.models.ContentType doesn't declare an explicit app_label and       
isn't in an application in `INSTALLED_APPS`.
</code></pre>

<p><strong>HOWEVER:
Here it is in INSTALLED_APPS--</strong></p>

<pre><code>WSGI_APPLICATION = 'mysite.wsgi.application'
import django
django.setup()

# Application definition

INSTALLED_APPS = [
                    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',

    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'django_comments',
    'django_comments_xtd',
    'django.contrib.sites',
    'accounts.apps.AccountsConfig',
    'posts.apps.PostsConfig',

    'category',
    #'vote',
    'tinymce',
    'django_wysiwyg',
    'follow',

    'djrichtextfield',
    'ckeditor',
    #'likes',
    'secretballot',

    'hitcount',
    #'pinax',
    'pinax.likes',

    #'pinax',
    #'pinax_theme_bootstrap',
    #'bootstrapform',

    #'voting',
    'actstream',


]
</code></pre>

<p>What could be causing this? It's explicitly stated in Installed_Apps, as you can see.</p>