StaleElementReferenceExceptions in Selenium Webdriver

This Exception occurs when driver is trying to perform action on the element which is no longer exists or not valid.

WebElement ele = driver.findElement(By.id("sample"));
// Before clicking some thing happened and DOM has changed due to page refresh, or element is removed and re-added
ele.click();

Now at this point, the element which you're clicking is no longer valid.

so it throws up its hands and gives control to user, who as the test/app author should know exactly what may or may not happen.

In order overcome this, we need to explicitly wait until the DOM is in a state where we are sure that DOM won't change.

For example, using a WebDriverWait to wait for a specific element to exist:

/ times out after 10 seconds
WebDriverWait wait = new WebDriverWait(driver, 10);

// while the following loop runs, the DOM changes - 
// page refreshed, or element removed and re-added
wait.until(elementIdentified(By.id("element")));        

// now we're good - let's click the element
driver.findElement(By.id("sample")).click();

private static Function<WebDriver,WebElement> elementIdentified(final By locator) {
    return new Function<WebDriver, WebElement>() {
        @Override
        public WebElement apply(WebDriver driver) {
            return driver.findElement(locator);
        }
    };
}

You can also user implicit waits, in which Webdriver will check for the element to become present until the specified timeout:

driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS)