Sometimes old, corrupted temporary files prevent the driver from starting.
driver = new FirefoxDriver(); // your test code here
If Firefox is installed in a non-standard directory, explicitly provide the path using FirefoxOptions.BinaryLocation . Sometimes old, corrupted temporary files prevent the driver
Driver?.Quit(); Driver?.Dispose();
If you prefer the "old school" way or cannot use NuGet packages due to corporate restrictions, you are likely manually downloading geckodriver.exe . If you are doing this, the error usually stems from the fact that the FirefoxDriver class cannot locate the file. If you are doing this, the error usually
var service = FirefoxDriverService.CreateDefaultService(@"C:\Path\To\GeckoDriver\"); service.FirefoxBinaryPath = @"C:\Program Files\Mozilla Firefox\firefox.exe"; var driver = new FirefoxDriver(service); Use code with caution. Copied to clipboard (Refer to Stack Overflow for implementation details)
This issue is rarely a bug in Selenium itself and is usually caused by environment or configuration factors: Temporarily disable your antivirus or add an exception
Sometimes local firewall settings block the http://localhost connection. Temporarily disable your antivirus or add an exception for geckodriver.exe and Firefox. Example of a Stable Firefox Setup in C#
To resolve the " Cannot start the driver service on http://localhost