Cannot Start The Driver Service On Http Localhost Selenium Firefox C

service = Service(executable_path='geckodriver.exe', service_args=['--log', 'debug']) service.start() # Manual start with longer timeout

When a test crashes or is abruptly terminated, the GeckoDriver process often continues running in the background, still holding onto its allocated port. When your next test runs, Selenium attempts to start a new driver service on a new port, but the orphaned process interferes with the initialization sequence.

Set the timeout to at least 60 seconds.

using OpenQA.Selenium.Firefox;

If your development machine sits behind a corporate proxy server, that proxy can intercept the local HTTP communication between Selenium and GeckoDriver. The driver service attempts to bind to localhost , but your system's proxy settings may be redirecting or blocking this traffic.

This is arguably the most frequent cause. Your project may be referencing outdated or incompatible driver packages. For example, if you have Selenium.Firefox.WebDriver version 0.27.0 installed alongside Selenium.WebDriver version 4.1.0 , the older GeckoDriver version (0.27.0) cannot properly communicate with the newer Selenium bindings.

Old versions of Selenium libraries can have trouble with modern browsers. Open NuGet Package Manager in Visual Studio. Update Selenium.WebDriver . service = Service(executable_path='geckodriver

Your Selenium WebDriver, GeckoDriver, and Firefox versions are out of sync. 🚀 Top Solutions 1. Hardcode the Loopback Address

If automatic driver management fails, you can explicitly provide the path to your GeckoDriver executable. First, download the correct GeckoDriver version from the official Mozilla releases page and place it in your project directory.

Open your terminal and run killall geckodriver or killall firefox . using OpenQA

service = FirefoxDriverService.CreateDefaultService(@"C:\path\to\geckodriver\folder"); FirefoxDriver(service); Use code with caution. Copied to clipboard 4. Check Local Network/Hosts Settings The driver service needs to bind to

If you have geckodriver.exe in your project folder, you must tell Selenium where it is.