■スタックトレースを見ると後半で下記の様になっています。
File "C~\site-packages\selenium\webdriver\remote\webdriver.py", line 252, in start_session
response = self.execute(Command.NEW_SESSION, parameters)
File "C~\site-packages\selenium\webdriver\remote\webdriver.py", line 321, in execute
self.error_handler.check_response(response)
File "C~\site-packages\selenium\webdriver\remote\errorhandler.py", line 208, in check_response
raise exception_class(value)
selenium.common.exceptions.WebDriverException: Message: Unknown error