вход в систему через multipart / form-data получить ошибку 400

Question

Я пытаюсь войти, используя следующий код:

# -*- coding: utf-8 -*-
from datetime import datetime
from requests_toolbelt import MultipartEncoder
import traceback
import scrapy
import Utils.GeneralUtils as utils
import Utils.DbUtils as du
import dateparser as dp
from datetime import datetime
import math

DEBUG = False


class InnerException(Exception):
  '''
  workaround for inner exception of parse_insert_comment
  only for parse_post_page to use to keep raising
  exception as i.args[0]

  some unregistered user will cause user_name.strip()
  NoneType error
  Ignore those users / comments / posts
  '''
  pass


class WbcSpider(scrapy.Spider):
  '''
  yield_dict: mandantory keys
    db_handler
    meta_dict
    error
    result
  '''
  name = 'wbc'

  def __init__(self):
    super().__init__()
    self.start_ric_url_dict = {
        'wbc': 'https://hotcopper.com.au/asx/wbc/discussion/?post_view=0'
    }

    # flags' dict for determing whether keep scraping
    self.comment_cont_dict = dict()
    self.post_cont_dict = dict()
    self.max_old_num = 5
    self.stop_date_flag = dp.parse('2018-12-31')
    self.scrapy_meta_keys = [
        'depth', 'download_timeout', 'download_slot', 'download_latency', '_id'
    ]

    # self.exchange = ExchangeParser()
    # private
    # if self.exchange.is_multi_source_exchange:
    # self.latest_date = utils.create_date_time_tzinfo('30 DEC 2017',
    #                                                  self.exchange.tzinfo)

  def start_requests(self):
    form_data = {
        'login': '***',
        'password': '***',
        'remember': '1',
        'cookie_check': '1',
        'tos': '1',
        'redirect': 'https://hotcopper.com.au/',
        '_xfToken': '',
        '_xfResponseType': 'json',
        '_xfRequestUri': '/login/'
    }

    boundary = '----WebKitFormBoundaryKJHwhAZcqb1VwurG'
    encoder = MultipartEncoder(form_data, boundary)
    headers = {
        'Content-Type':
            'multipart/form-data; boundary=----WebKitFormBoundaryKJHwhAZcqb1VwurG',
        'Content-Length':
            encoder.len
    }

    yield scrapy.Request(
        url='https://hotcopper.com.au/login/login',
        method='POST',
        body=encoder.to_string(),
        headers=headers,
        callback=self.after_login,
        dont_filter=True)

  def after_login(self, response):
    from scrapy.shell import inspect_response
    inspect_response(response, self)
    for ric, url in self.start_ric_url_dict.items():
      yield scrapy.Request(url, callback=self.parse_forum_page)
      if DEBUG:  # only one market
        break

Я перешел по этой ссылке Как правильно сделать запрос к форме "multipart / form-data" с помощью Scrapy? для запроса POST multipart / form. Тем не менее, Scrap возвращает мне эту ошибку:

2019-06-07 01:24:14 [scrapy.spidermiddlewares.httperror] INFO: Ignoring response <400 https://hotcopper.com.au/login/login>: HTTP status code is not handled or not allowed

Какую ошибку я совершил?