AttributeError: 'Overview' object has no attribute '__qualname__' - django

Question

I am updating Django from 1.11.27 to 2.2.9 - python2.7 to python3.7 - made all the changes, but when I start server I have this error.
AttributeError: 'Overview' object has no attribute '__qualname__'
Traceback (most recent call last):
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
response = get_response(request)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/contextlib.py", line 74, in inner
return func(*args, **kwds)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/contrib/admin/sites.py", line 241, in wrapper
return self.admin_view(view, cacheable)(*args, **kwargs)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/utils/decorators.py", line 142, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/views/decorators/cache.py", line 44, in _wrapped_view_func
response = view_func(request, *args, **kwargs)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/contrib/admin/sites.py", line 213, in inner
if request.path == reverse('admin:logout', current_app=self.name):
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/urls/base.py", line 58, in reverse
app_list = resolver.app_dict[ns]
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/urls/resolvers.py", line 513, in app_dict
self._populate()
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/urls/resolvers.py", line 464, in _populate
url_pattern._populate()
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/urls/resolvers.py", line 464, in _populate
url_pattern._populate()
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/urls/resolvers.py", line 452, in _populate
self._callback_strs.add(url_pattern.lookup_str)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/utils/functional.py", line 80, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/Users/user/Sites/project-folder/venv/lib/python3.7/site-packages/django/urls/resolvers.py", line 362, in lookup_str
return callback.__module__ + "." + callback.__qualname__
AttributeError: 'Overview' object has no attribute '__qualname__'
Found the exception here (Django 2.2.9):
https://github.com/django/django/blob/master/django/urls/resolvers.py#L361
#cached_property
def lookup_str(self):
"""
A string that identifies the view (e.g. 'path.to.view_function' or
'path.to.ClassBasedView').
"""
callback = self.callback
if isinstance(callback, functools.partial):
callback = callback.func
if not hasattr(callback, '__name__'):
return callback.__module__ + "." + callback.__class__.__name__
return callback.__module__ + "." + callback.__qualname__