ALLOWED_HOSTS = [] is problematic

[KabirKanha]

From documentation: https://docs.djangoproject.com/en/1.10/ref/settings/

if DEBUG is False, you also need to properly set the ALLOWED_HOSTS setting. Failing to do so will result in all requests being returned as “Bad Request (400)

Additional reference: https://stackoverflow.com/questions/24857158/commanderror-you-must-set-settings-allowed-hosts-if-debug-is-false