title: Sudden error with Django 'python manage.py runserver'
body: <p>Recently I started a Django project, created a model, then registered it in <code>admin.py</code> in the same app file.  I then got this strange error:</p>
  <pre><code>(djangoEnv) C:\Users\*****\sample_project&gt;python manage.py runserver
  Watching for file changes with StatReloader
  Exception in thread django-main-thread:
  Traceback (most recent call last):
    File &quot;C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.1264.0_x64__qbz5n2kfra8p0\lib\threading.py&quot;, line 1009, in _bootstrap_inner
      self.run()
    File &quot;C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.1264.0_x64__qbz5n2kfra8p0\lib\threading.py&quot;, line 946, in run
      self._target(*self._args, **self._kwargs)
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\utils\autoreload.py&quot;, line 64, in wrapper
      fn(*args, **kwargs)
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\core\management\commands\runserver.py&quot;, line 125, in inner_run
      autoreload.raise_last_exception()
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\utils\autoreload.py&quot;, line 87, in raise_last_exception
      raise _exception[1]
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\core\management\__init__.py&quot;, line 398, in execute
      autoreload.check_errors(django.setup)()
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\utils\autoreload.py&quot;, line 64, in wrapper
      fn(*args, **kwargs)
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\__init__.py&quot;, line 24, in setup
      apps.populate(settings.INSTALLED_APPS)
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\apps\registry.py&quot;, line 124, in populate
      app_config.ready()
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\contrib\admin\apps.py&quot;, line 27, in ready
      self.module.autodiscover()
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\contrib\admin\__init__.py&quot;, line 50, in autodiscover
      autodiscover_modules(&quot;admin&quot;, register_to=site)
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\utils\module_loading.py&quot;, line 58, in autodiscover_modules
      import_module(&quot;%s.%s&quot; % (app_config.name, module_to_search))
    File &quot;C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.1264.0_x64__qbz5n2kfra8p0\lib\importlib\__init__.py&quot;, line 126, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 1050, in _gcd_import
    File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 1027, in _find_and_load
    File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 1006, in _find_and_load_unlocked
    File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 688, in _load_unlocked
    File &quot;&lt;frozen importlib._bootstrap_external&gt;&quot;, line 883, in exec_module
    File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 241, in _call_with_frames_removed
    File &quot;C:\Users\roanr\sample_project\projects\admin.py&quot;, line 6, in &lt;module&gt;
      admin.site.register(project)
    File &quot;C:\Users\*****\djangoEnv\lib\site-packages\django\contrib\admin\sites.py&quot;, line 117, in register
      for model in model_or_iterable:
  TypeError: 'type' object is not iterable
  </code></pre>
  <p>Here's the model:</p>
  <pre><code>from django.db import models
  
  # Create your models here.
  class project():
      title       = models.TextField()
      githubLink  = models.TextField(default=&quot;No Github link.&quot;)
  </code></pre>
  <p>Why is it doing this, and how can it be fixed?
  FYI: it does the same thing with <code>python manage.py makemigrations</code> and <code>python manage.py migrate</code>.
  Thanks a lot to anyone who knows what's going on.</p>