Pythonのスクレイピングコードでsend_keysエラー発生

#!/usr/bin/python3

import os

from selenium import webdriver
from selenium.webdriver.chrome.options import Options
from selenium.webdriver.common.keys import Keys

# headless chrome

options = Options()
options.binary_location = '/Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary'
options.add_argument('--headless')
options.add_argument('--window-size=1280,3000')

driver = webdriver.Chrome(chrome_options=options)
driver.get("https://example.com")
driver.find_element_by_xpath("//*[@id='email']").send_keys("[email protected]")
driver.find_element_by_xpath("//*[@id='password']").send_keys("hogehoge" + Keys.RETURN)

 File “sample.py”, line 28, in <module>
   send_keys(‘[email protected]’)
 File “/Users/:user/.pyenv/versions/anaconda3-4.3.0/lib/python3.6/site-packages/selenium/webdriver/remote/webelement.py”, line 479, in send_keys
   ‘value’: keys_to_typing(value)})
 File “/Users/:user/.pyenv/versions/anaconda3-4.3.0/lib/python3.6/site-packages/selenium/webdriver/remote/webelement.py”, line 628, in _execute
   return self._parent.execute(command, params)
 File “/Users/:user/.pyenv/versions/anaconda3-4.3.0/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py”, line 312, in execute
   self.error_handler.check_response(response)
 File “/Users/:user/.pyenv/versions/anaconda3-4.3.0/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py”, line 237, in check_response
   raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: unknown error: call function result missing ‘value’
 (Session info: headless chrome=66.0.3329.1)
 (Driver info: chromedriver=2.33.506106 (8a06c39c4582fbfbab6966dbb1c38a9173bfb1a2),platform=Mac OS X 10.13.3 x86_64)