[Django]デバッグツールバーの作成中にエラーが発生

前提・実現したいこと

現在、Djangoで初のWeb開発をしています。
そこでデバッグツールバーを表示させようと思い、pipで、django-debug-toolbarを導入してからsettings.pyやurls.pyをいじっていました。
settings.pyのMIDDLEWAREに'debug_toolbar.middleware.DebugToolbarMiddleware', を加えると以下のエラーが発生してしまいました。

発生している問題・エラーメッセージ

binascii.Error: Invalid base64-encoded string: number of data characters (213) cannot be 1 more than a multiple of 4

このエラーを調べてみると、データを4文字区切りにしないとダメなようなのですが、どこをどのように区切ればいいのかわかりません。

ご教示してもらえるとありがたいです。

問題が発生するまでの流れ

  MIDDLEWARE = [
      'django.middleware.security.SecurityMiddleware',
      'django.contrib.sessions.middleware.SessionMiddleware',
      'django.middleware.common.CommonMiddleware',
      'django.middleware.csrf.CsrfViewMiddleware',
      'django.contrib.auth.middleware.AuthenticationMiddleware',
      'django.contrib.messages.middleware.MessageMiddleware',
      'django.middleware.clickjacking.XFrameOptionsMiddleware',
+     'debug_toolbar.middleware.DebugToolbarMiddleware', # Deubg tool bar
  ]

+の行を加えるとエラーが発生します。

エラーの全貌

Internal Server Error: /
Traceback (most recent call last):
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 199, in _get_session
    return self._session_cache
AttributeError: 'SessionStore' object has no attribute '_session_cache'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/core/handlers/base.py", line 145, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/core/handlers/base.py", line 143, in _get_response
    response = response.render()
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/template/response.py", line 105, in render
    self.content = self.rendered_content
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/template/response.py", line 83, in rendered_content
    return template.render(context, self._request)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/template/base.py", line 171, in render
    return self._render(context)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/test/utils.py", line 94, in instrumented_test_render
    template_rendered.send(sender=self, template=self, context=context)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/dispatch/dispatcher.py", line 173, in send
    return [
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/dispatch/dispatcher.py", line 174, in <listcomp>
    (receiver, receiver(signal=self, sender=sender, **named))
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/debug_toolbar/panels/templates/panel.py", line 103, in _store_template_info
    if isinstance(value, http.HttpRequest):
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/utils/functional.py", line 224, in inner
    self._setup()
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/utils/functional.py", line 360, in _setup
    self._wrapped = self._setupfunc()
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/auth/middleware.py", line 24, in <lambda>
    request.user = SimpleLazyObject(lambda: get_user(request))
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/auth/middleware.py", line 12, in get_user
    request._cached_user = auth.get_user(request)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/auth/__init__.py", line 173, in get_user
    user_id = _get_user_session_key(request)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/auth/__init__.py", line 58, in _get_user_session_key
    return get_user_model()._meta.pk.to_python(request.session[SESSION_KEY])
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 64, in __getitem__
    return self._session[key]
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 204, in _get_session
    self._session_cache = self.load()
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/db.py", line 44, in load
    return self.decode(s.session_data) if s else {}
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 110, in decode
    encoded_data = base64.b64decode(session_data.encode('ascii'))
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/base64.py", line 87, in b64decode
    return binascii.a2b_base64(s)
binascii.Error: Invalid base64-encoded string: number of data characters (213) cannot be 1 more than a multiple of 4
Internal Server Error: /
Traceback (most recent call last):
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 199, in _get_session
    return self._session_cache
AttributeError: 'SessionStore' object has no attribute '_session_cache'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/debug_toolbar/middleware.py", line 67, in __call__
    panel.generate_stats(request, response)
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/debug_toolbar/panels/request.py", line 57, in generate_stats
    for k in sorted(request.session.keys())
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 135, in keys
    return self._session.keys()
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 204, in _get_session
    self._session_cache = self.load()
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/db.py", line 44, in load
    return self.decode(s.session_data) if s else {}
  File "/Users/mizutanikizashi/venv/lib/python3.9/site-packages/django/contrib/sessions/backends/base.py", line 110, in decode
    encoded_data = base64.b64decode(session_data.encode('ascii'))
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/base64.py", line 87, in b64decode
    return binascii.a2b_base64(s)
binascii.Error: Invalid base64-encoded string: number of data characters (213) cannot be 1 more than a multiple of 4