[Answered ]-Page not found grappelli-django install

Change your INSTALLED_APPS like so:

INSTALLED_APPS = (
    'grappelli',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    #'south',
    'app_salon',
    'app_agenda',
)

And make sure you have the following settings:

STATICFILES_FINDERS = (
    'django.contrib.staticfiles.finders.AppDirectoriesFinder',
    'django.contrib.staticfiles.finders.FileSystemFinder',
)

TEMPLATE_CONTEXT_PROCESSORS = (
    ...
    "django.core.context_processors.request",
)

Then collect media files:

$ python manage.py collectstatic

Source: https://django-grappelli.readthedocs.org/en/latest/quickstart.html