ERROR app::main: 'pop from an empty set'

[ghdna]

Not sure if the website has updated since the Selenium script or if there is something wrong here. Unable to get past login screen due to 'pop from an empty set' error. Any ideas?

11:42:35 INFO app::__enter__: Starting xvfb display
11:42:35 INFO app::__enter__: Starting browser
11:42:37 INFO app::navigate_url: Navigating to 'http://tadpoles.com/'
11:42:39 INFO app::load_cookies: Loading cookies.
11:42:39 INFO app::do_login: Navigating to login page.
11:42:41 INFO app::switch_windows: Switching windows.
11:42:41 ERROR app::main: 'pop from an empty set'
Traceback (most recent call last):
  File "app.py", line 260, in download_images
    self.load_cookies()
  File "app.py", line 111, in load_cookies
    with open(self.COOKIE_FILE, "rb") as f:
FileNotFoundError: [Errno 2] No such file or directory: 'state/cookies.pkl'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "app.py", line 280, in main
    client.download_images()
  File "app.py", line 262, in download_images
    self.do_login()
  File "app.py", line 148, in do_login
    self.switch_windows()
  File "app.py", line 137, in switch_windows
    other_window = (all_windows - current_window).pop()
KeyError: 'pop from an empty set'
11:42:41 INFO app::__exit__: Shutting down browser
11:42:43 INFO app::__exit__: Shutting down xfvb display