通过geckodriver的Selenium Firefox Webdriver导致错误:无法启动浏览器:找不到实体

我正在使用:

• 硒3.0.1版
• Firefox版本47 64位
• Windows 10
• geckodriver版本11

我的代码:

from selenium import webdriver
from selenium.webdriver.firefox.firefox_binary import FirefoxBinary

binary=FirefoxBinary('C:\Program Files\Mozilla Firefox\firefox.exe')
wb=webdriver.Firefox(firefox_binary=binary)
wb.get("www.python.org")

错误消息:

   wb=webdriver.Firefox(firefox_binary=binary)
  File "c:\Python34\lib\site-packages\selenium\webdriver\firefox\webdriver.py", line 145, in __init__
    keep_alive=True)
  File "c:\Python34\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 92, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "c:\Python34\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 179, in start_session
    response = self.execute(Command.NEW_SESSION, capabilities)
  File "c:\Python34\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 236, in execute
    self.error_handler.check_response(response)
  File "c:\Python34\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 192, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Failed to start browser: entity not found