Cannot Start The Driver Service On Http Localhost Selenium Firefox C «Desktop»

firefox --version If this fails, Firefox cannot be found in your PATH .

For Java:

from pyvirtualdisplay import Display display = Display(visible=0, size=(1920, 1080)) display.start() # Your Firefox driver code here Sometimes, GeckoDriver starts the HTTP server slowly (slow disk, high CPU). Selenium’s default timeout of 20 seconds expires, and it kills the process. firefox --version If this fails, Firefox cannot be

sudo apt-get install xvfb xvfb-run python your_selenium_script.py Or, use PyVirtualDisplay in Python:

Using port=7055 often resolves conflicts because it's a reserved port for WebDriver. On Windows, SmartScreen or Windows Defender may quarantine or silently block geckodriver.exe because it opens a network port (behavior associated with malware). If it fails, the entire service crashes with

This error is Selenium’s way of saying: “I tried to launch Firefox, but the bridge (GeckoDriver) connecting me to the browser collapsed before the connection could be established.”

from selenium.webdriver.firefox.service import Service service = Service(executable_path='path/to/geckodriver', port=7055) # Classic Selenium port driver = webdriver.Firefox(service=service) If it fails

from selenium.webdriver.firefox.options import Options options = Options() options.binary_location = r'C:\Program Files\Mozilla Firefox\firefox.exe' # Windows driver = webdriver.Firefox(options=options) Cause 5: The Headless/Background Mode Trap When running Selenium on a headless server (Linux without a GUI, or Docker container), GeckoDriver attempts to create a graphical display. If it fails, the entire service crashes with the localhost error.