19👍
The problem was in middlewares order.
CommonMiddleware returns HttpResponsePermanentRedirect in cases when to request url have been added ‘www’ or trailing ‘/’ (APPEND_SLASH and PREPEND_WWW in settings). In such case django stops looking through middleware list for process_request methods and begins to run process_response methods.
It’s bad there is no information about such behavior for standard django middlewares (i.e. middleware could return in some cases HttpResponse object).
5👍
If you came here because you updated to Django 2.0 and get this error, you might want to know that name MIDDLEWARE_CLASSES was replaced with MIDDLEWARE.
More here https://stackoverflow.com/a/47650447/1218179 and here https://docs.djangoproject.com/en/2.0/topics/http/middleware/