GeckoDriver not working in C# for Firefox browser

Question

I'm trying to run some unit tests using Selenium Webdriver and C#.Net for Firefox browser but I was unable to do it (Chrome and IE11 browsers are working smoothly).

Here is the info I gathered:

OS: Windows 10 Enterprise

Gecko driver version: geckodriver-v0.17.0-win32

Mozilla Firefox version: 54.0.1 (32-bit)

Environment Path variable already set under "C:\LEO\SELENIUM C#\Firefox"

Piece of Code:

using System;
using System.Text;
using System.Threading;
using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Support.UI;
using OpenQA.Selenium.Firefox;

[TestFixture]
public class UnitTest3
{
    private IWebDriver driver;
    private StringBuilder verificationErrors;
    private string baseURL;

    [SetUp]
    public void SetupTest()
    {
        FirefoxDriverService service = FirefoxDriverService.CreateDefaultService(@"C:\LEO\SELENIUM C#\Firefox");
        service.FirefoxBinaryPath = @"C:\Program Files (x86)\Mozilla Firefox\firefox.exe";
        driver = new FirefoxDriver(service);
        baseURL = "http://www.dow.com";
        verificationErrors = new StringBuilder();
    }
}

Error:

Message: OpenQA.Selenium.WebDriverException : Unable to find a matching set of capabilities.

TearDown : System.NullReferenceException : Object reference not set to an instance of an object.

StackTrace:

I will appreciate all your help, thanks.

Answer 1

Simple solution:

• use NuGet to download the Firefox driver into your project
• Geckodriver.exe should now be available in your solution explorer (see screenshot)
• Make sure you set the property to Copy if newer (or Copy always)
• Then simply use the code IWebDriver driver = new FirefoxDriver();, because the driver file will always be copied to your bin folder you don't need to reference an explicit path

Answer 2

If the browser is not installed in the default location maybe it is good to specify the BrowserExecutableLocation.

 FirefoxOptions firefoxOptions = new FirefoxOptions();
 firefoxOptions.AcceptInsecureCertificates = true;
 firefoxOptions.BrowserExecutableLocation = @"C:\your\location\Mozilla Firefox\Firefox.exe";
 driver = new FirefoxDriver(firefoxOptions);