Disable any "Manual proxy setup" in Windows settings that might interfere with local addresses.
Check your for any background instances of geckodriver.exe or firefox.exe and end them. You can automate this via the command line as an administrator: taskkill /f /im geckodriver.exe taskkill /f /im firefox.exe 3. Handle Proxy and Loopback Settings Disable any "Manual proxy setup" in Windows settings
A common mistake is passing the path to the Firefox browser ( firefox.exe Disable any "Manual proxy setup" in Windows settings
: Cannot start the driver service on http://localhost:4444/ Disable any "Manual proxy setup" in Windows settings