Cannot Start The Driver Service On Http Localhost Selenium Firefox C

Use FirefoxDriverService to explicitly define the driver path. Advanced Fixes

Download the executable and place it in a known folder. Code: Specify the path directly in your C# code:

: Ensure you aren't trying to run a 64-bit driver on a 32-bit OS, or vice versa.

Open your terminal and run killall geckodriver or killall firefox .

: If the default port is blocked, you can manually assign a port using FirefoxDriverService.CreateDefaultService().Port = 9222 .

The error "cannot start the driver service on http://localhost" means the failure happened at . The GeckoDriver process either died immediately after starting, or it failed to spin up the HTTP listener within the timeout window (typically 20 seconds).

Happy Testing