Why my test is throwing Exception-Unable to locate element in webdriver?

Question

package testproject;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.*;
          


        

Answer 1

//launch browser 
FirefoxDriver driver = new FirefoxDriver(options); 
driver.manage().timeouts().implicitlyWait(50, TimeUnit.SECONDS);
//gmail login :
driver.get("http://www.gmail.com");
driver.findElement(By.id("identifierId")).sendKeys("****",Keys.ENTER);
Thread.sleep(5000);
driver.findElement(By.id("password")).sendKeys("***",Keys.ENTER);
//logout:
driver.findElement(By.xpath("//div[@id='gb']/div[1]/div[1]/div[2]/div[4]/div[1]/a/span")).click();
Thread.sleep(5000);
driver.findElement(By.linkText("Sign out")).click();