ImportError: Не удалось импортировать «formshare.libs.authentication.DigestAuthentication» для настройки API «DEFAULT_AUTHENTICATION_CLASSES»

Question

Мое приложение Django не выдает никаких ошибок при запуске python manage.py runserver, но все еще не работает после полной настройки.Ниже приведена трассировка журнала ошибок.

class APIView(View):
File "/opt/formshare/lib/python2.7/site-packages/rest_framework/views.py", line 88, in APIView
authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
File "/opt/formshare/lib/python2.7/site-packages/rest_framework/settings.py", line 197, in __getattr__
val = perform_import(val, attr)
File "/opt/formshare/lib/python2.7/site-packages/rest_framework/settings.py", line 149, in perform_import
return [import_from_string(item, setting_name) for item in val]
File "/opt/formshare/lib/python2.7/site-packages/rest_framework/settings.py", line 165, in import_from_string
raise ImportError(msg)
ImportError: Could not import 'formshare.libs.authentication.DigestAuthentication' for API setting 'DEFAULT_AUTHENTICATION_CLASSES'. ImportError: No module named related.

.

Installed application requirements 
    # Django
    pybamboo==0.5.8.1
    Django>=1.6,<1.7
    django-guardian==1.2.4
    django-registration-redux==1.1
    django-templated-email==0.4.9
    gdata==2.0.18
    httplib2==0.9
    mock==1.0.1
    httmock==1.2.2
    modilabs-python-utils==0.1.5
    Pillow==2.5.3
    poster==0.8.1
    psycopg2==2.8.3
    pymongo==2.7.2
    lxml==3.4.0
    django-nose==1.4.2
    pandas==0.20.3
    South==1.0
    django-reversion==1.8.4
    xlrd==1.1.0
    xlwt==0.7.5
    openpyxl==2.0.5
    celery==3.1.23
    django-celery==3.1.17
    librabbitmq==1.5.2
    python-digest==1.7
    django-digest==1.13
    requests==2.4.1
    elaphe==0.5.6
    # sms support
    dict2xml==1.3
    # api support
    djangorestframework==2.4.3
    djangorestframework-csv==1.3.3
    # cors
    django-cors-headers==0.13
    Markdown==2.5
    django-filter==0.7
    # captcha
    recaptcha-client==1.0.6
    unicodecsv==0.14.1
    dpath==1.2-70
    # tagging
    django-taggit==0.12.1
    # oath2 support
    django-oauth-toolkit==0.7.2

    # spss
    savReaderWriter

    # JSON data type support
    jsonfield<1.0
    django-db-readonly==0.3.2

    # memcached support
    pylibmc==1.3.0
    kombu==3.0.35
    billiard==3.3.0.23
    python-dateutil==2.6.0

Любые советы о том, как это исправить, будут высоко оценены.

Спасибо.Коллинз