org.openqa.selenium.SessionNotCreatedException: Unable to find a matching set of capabilities while initiating Firefox v37 through Selenium v3.11.0

Question

I am trying to run test a run a website in Firefox, but I am getting error "The path to the driver executable must be set by the webdriver.gecko.driver system property;" I have set the path correctly, still don't know where the problem is. Here is my code:

if (browsers.equalsIgnoreCase("Firefox")) 
{
        String driverPath = System.getProperty("user.dir") + "\src/test/java\drivers\geckodriver.exe";
        System.setProperty("webdriver.firefox.marionette", "false");
        driver = new FirefoxDriver();
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
    } else if (browsers.equalsIgnoreCase("Chrome")) {
        // String driverPath = System.getProperty("user.dir") +
        // "\src\Drivers\chromedriver";
        // System.setProperty("webdriver.chrome.driver", driverPath);
        System.setProperty("webdriver.chrome.driver", "D:\chromedriver.exe");
        driver = new ChromeDriver();
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);

    }

Here is the Failure Trace of my code:

FAILED CONFIGURATION: @BeforeClass launchBrowser
org.openqa.selenium.SessionNotCreatedException: Unable to find a matching set of capabilities
Build info: version: '3.8.0', revision: '924c4067df', time: '2017-11-30T11:36:59.109Z'
System info: host: 'DSCHD-PC-180', ip: '192.168.6.122', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_161'
Driver info: driver.version: FirefoxDriver
remote stacktrace: 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.openqa.selenium.remote.W3CHandshakeResponse.lambda$new$0(W3CHandshakeResponse.java:57)
    at org.openqa.selenium.remote.W3CHandshakeResponse.lambda$getResponseFunction$2(W3CHandshakeResponse.java:104)
    at org.openqa.selenium.remote.ProtocolHandshake.lambda$createSession$0(ProtocolHandshake.java:123)
    org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:126)
    at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:73)
    at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:142)
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:83)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:601)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:219)
    at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:142)
    at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:120)
    at Utility.UtilityMethods.openBrowser(UtilityMethods.java:26)
    at TestCases.LoginTestCase.launchBrowser(LoginTestCase.java:35)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:124)
    at org.testng.internal.MethodInvocationHelper.invokeMethodConsideringTimeout(MethodInvocationHelper.java:59)
    at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:455)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:222)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:142)
    at org.testng.internal.TestMethodWorker.invokeBeforeClassMethods(TestMethodWorker.java:168)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:105)
    at org.testng.TestRunner.privateRun(TestRunner.java:648)
    at org.testng.TestRunner.run(TestRunner.java:505)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:455)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:450)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:415)
    at org.testng.SuiteRunner.run(SuiteRunner.java:364)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:84)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1208)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1137)
    at org.testng.TestNG.runSuites(TestNG.java:1049)
    at org.testng.TestNG.run(TestNG.java:1017)
    at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:114)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)

SKIPPED CONFIGURATION: @AfterClass quitBrowser
SKIPPED: registration   

Answer 1

To keep things simple, as you are using Selenium Client v3.11.0 and Firefox v37 you need to download the latest GeckoDriver from mozilla/geckodriver and save it any where within your system. Next within the System.setProperty() line pass the Key webdriver.gecko.driver along with the Value as the absolute path of the GeckoDriver and finally through DesiredCapabilities class set the capability marionatte to false and merge into an instance of FirefoxOptions instance to initiate the Firefox browser as follows :

System.setProperty("webdriver.gecko.driver", "C:/path/to/geckodriver.exe");
DesiredCapabilities dc = new DesiredCapabilities();
dc.setCapability("marionatte", false);
FirefoxOptions opt = new FirefoxOptions();
opt.merge(dc);
FirefoxDriver driver =  new FirefoxDriver(opt);
driver.get("https://stackoverflow.com");
System.out.println("Application opened");
System.out.println("Page Title is : "+driver.getTitle());
driver.quit();

---

Update

As per your comment update you are using GeckoDriver v0.20.1.

But if you look back at the Release Notes of GeckoDriver v0.18.0 it clearly mentions :

geckodriver now recommends Firefox 53 and greater

So using GeckoDriver v0.18.0 and above you have to mandatory use Firefox 53 and greater. To get rid of this constraint you can downgrade either to any of these versions :

• GeckoDriver v0.17.0
• GeckoDriver v0.16.1