File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/firefox/webdriver.py", line 152, in __init__ keep_alive=True) File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 98, in __init__ self.start_session(desired_capabilities, browser_profile) File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 185, in start_session response = self.execute(Command.NEW_SESSION, parameters) File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 249, in execute self.error_handler.check_response(response) File "/root/venv/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response raise exception_class(message, screen, stacktrace) selenium.common.exceptions.WebDriverException: Message: Unable to find a matching set of capabilities