Cannot Start The Driver Service On Http Localhost Selenium Firefox C Jun 2026

from selenium.webdriver.firefox.options import Options

Check the compatibility matrix for your environment: from selenium

using (IWebDriver driver = new FirefoxDriver()) try driver.Navigate().GoToUrl("https://google.com"); catch (Exception ex) Console.WriteLine($"Error: ex.Message"); // Automatically calls Quit() and closes the service Use code with caution. 🔍 Troubleshooting Summary Ensure port 4444 (or your custom port) is free. Path Verify geckodriver.exe is in your bin folder. VPN Turn off VPNs, as they can sometimes reroute local traffic. Permissions Run Visual Studio as Administrator. VPN Turn off VPNs, as they can sometimes

Cannot start the driver service on http://localhost · Issue #372 · mozilla/geckodriver This blocker halts automation routines immediately at the

The error occurs in C# Selenium developments when GeckoDriver fails to initialize its local HTTP server. This blocker halts automation routines immediately at the new FirefoxDriver() instantiation step.

On Windows, GeckoDriver may be blocked by User Account Control (UAC). On Unix systems, the file may lack execute permissions.