Xpath is not working on MouseOver(CatMenu) in Selenium

There is problem about selenium for all web driver which cannot open mouseover menu.Altough assing to Xpath of element web driver cannot open Mouse Over (CatMenu) and log is that "Must provide a location for a move action".

i want to go n11.com web adress and over on Kitap, Müzik, Film, Oyun and click Kitap but its not working. Thank you

@Test

public void  startWebDriver(){
System.setProperty("webdriver.chrome.driver", "C://chromedriver.exe");
WebDriver driver = new ChromeDriver();
driver.manage().window().maximize();
driver.get("http://www.n11.com");


Actions act = new Actions(driver);
act.moveToElement(driver.findElement(By.xpath(".//*[@id='contentMain']/div/nav/ul/li[8]/a"))).perform();

}