Cannot Start The Driver Service On | Http Localhost Selenium Firefox C Work

The error is a common headache for C# developers using Selenium with Firefox. It typically means the GeckoDriver executable is unable to establish a local network connection to start its internal server. 🛠️ Root Causes Port Conflicts: Another process is using the default port. Loopback Issues: localhost isn't resolving to 127.0.0.1 .

var driverService = FirefoxDriverService.CreateDefaultService(); driverService.Host = "127.0.0.1"; // Force IPv4 IWebDriver driver = new FirefoxDriver(driverService); Use code with caution. 2. Update Drivers and Browser The error is a common headache for C#

Ensure Firefox is updated to the latest stable release. 3. Configure Firewall Exceptions Loopback Issues: localhost isn't resolving to 127

📍 Most "localhost" service errors are solved by explicitly setting the Host to 127.0.0.1 in the DriverService object. AI responses may include mistakes. Learn more Update Drivers and Browser Ensure Firefox is updated

If a previous debug session crashed, a "ghost" instance of GeckoDriver might still be holding onto the port. Open . End all tasks named geckodriver.exe . End all tasks named firefox.exe . 📋 Best Practices for C#