Cannot Start The Driver — Service On Http Localhost Selenium Firefox C

var driver = new FirefoxDriver(options); // will search PATH driver.Navigate().GoToUrl("https://example.com"); Console.WriteLine(driver.Title); driver.Quit();

Below, I break down exactly why this happens and the 7 most effective fixes. OpenQA.Selenium.WebDriverException: Cannot start the driver service on http://localhost:xxxx/ ---> System.Net.Sockets.SocketException: Only one usage of each socket address (protocol/network address/port) is normally permitted. Root Cause Analysis The error indicates a port conflict or driver process failure . The geckodriver tries to bind to a port on localhost , but something is blocking it. var driver = new FirefoxDriver(options); // will search

taskkill /F /IM geckodriver.exe

FirefoxDriverService service = FirefoxDriverService.CreateDefaultService(@"D:\drivers"); service.FirefoxBinaryPath = @"C:\Program Files\Mozilla Firefox\firefox.exe"; var driver = new FirefoxDriver(service); Sometimes a corrupted Firefox profile causes the driver to hang on startup. The geckodriver tries to bind to a port

pkill -f geckodriver

foreach (var process in Process.GetProcessesByName("geckodriver")) process.Kill(); Force a specific, free port to avoid conflicts. Introduction If you are automating Firefox using Selenium

Introduction If you are automating Firefox using Selenium WebDriver in C# (or any .NET language), you have likely encountered the dreaded WebDriverException : "Cannot start the driver service on http://localhost..." This error stops your automation dead in its tracks. It means Selenium cannot communicate with the geckodriver (the bridge between your code and Firefox).