Traceback (most recent call last):
  File "lecho360.py", line 88, in <module>
    main()
  File "lecho360.py", line 79, in main
    downloader.download_all()
  File "/media/karmanya/2E42E20D42E1D99B/Users/kdawg/Documents/GitHub/lecho360/EchoDownloader.py", line 24, in download_all
    videos = self._course.get_videos(self._driver).videos
  File "/media/karmanya/2E42E20D42E1D99B/Users/kdawg/Documents/GitHub/lecho360/EchoCourse.py", line 23, in get_videos
    course_data_json = self._get_course_data(driver)
  File "/media/karmanya/2E42E20D42E1D99B/Users/kdawg/Documents/GitHub/lecho360/EchoCourse.py", line 65, in _get_course_data
    json_str = driver.find_element_by_tag_name("pre").text
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 346, in find_element_by_tag_name
    return self.find_element(by=By.TAG_NAME, value=name)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 692, in find_element
    {'using': by, 'value': value})['value']
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 193, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py", line 181, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.NoSuchElementException: Message: {"errorMessage":"Unable to find element with css selector 'pre'","request":{"headers":{"Accept":"application/json","Accept-Encoding":"identity","Connection":"close","Content-Length":"94","Content-Type":"application/json;charset=UTF-8","Host":"127.0.0.1:35101","User-Agent":"Python-urllib/2.7"},"httpVersion":"1.1","method":"POST","post":"{\"using\": \"css selector\", \"sessionId\": \"3c9f3290-359a-11e5-8e1a-5df534c50e47\", \"value\": \"pre\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/3c9f3290-359a-11e5-8e1a-5df534c50e47/element"}}