Null pointer exception when click on element in mobile device

Issues/Bugs
1

I am using latest appium version: 1.7.1
With Capability : capabilities.setCapability(“automationName”, “UiAutomator2”);

-Launched an Amazon application.

  • WebElement ele =driver.findElement(By.id(“in.amazon.mShop.android.shopping:id/sign_in_button”));
    System.out.println(ele);
    ele.click();