Unable to click on submenu via selenium c# urgent

Question

i am new to automation testing and need some help. i want to click on child submenu but unable to do so. hirerachy of my menu is System->Manual->Manual Loader, how ever i am only successful in hovering main menu i.e. System. i am following the code given below. kindly help what to do

 

Note: Action builder is not working in my case or i am doing something wrong thats why it doesnt give the required output.

Actions builder = new Actions(driver);
// Move the cursor to the Main Menu Element (id1)
IWebElement menu = driver.FindElement(By.XPath("//*[@id='dvmenus']"));
builder.MoveToElement(menu);
IWebElement menuId = driver.FindElement(By.XPath("//a[contains(.,'System')]"));
//menuId.Click();
builder.MoveToElement(menuId);
WebDriverWait waitForControl = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
IWebElement submenuId = driver.FindElement(By.XPath("//a[contains(.,'Manual')]"));
builder.MoveToElement(submenuId);
//submenuId.Click();
WebDriverWait waitForControl1 = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
IWebElement childsubmenuId = driver.FindElement(By.XPath("//a[contains(.,'Manual Loader')]"));
builder.MoveToElement(childsubmenuId);
builder.Build().Perform();

i am getting this error on childsubmenuid.click "'element not interactable"