运行时错误：试图索引本地变量 'fay'（空值）。

我在尝试创建一个简单的菜单。我的程序在 Corona 模拟器中在 Windows 上编译正常，但是当我为 Android 构建程序时，它会收到“Runtime Error attempt to index local 'example1'（nil value）”。有人知道如何帮助我吗？非常感谢！！

这是更新后的代码

module (...,package.seeall)

function new()

    local menuGroup = display.newGroup()

    local background = display.newImage("graphics/background3.png")

    local example1 = display.newImage("graphics/Example1.png")
    example1.x = 720
    example1.y = 150
    example1.scene = "example1"

    local example2 = display.newImage("graphics/Example2.png")
    example2.x = 720
    example2.y = 450
    example2.scene = "example2"

    local example3 = display.newImage("graphics/Example3.png")
    example3.x = 720
    example3.y = 750
    example3.scene = "example3"

    local example4 = display.newImage("graphics/Example4.png")
    example4.x = 720
    example4.y = 1050
    example4.scene = "example4"

    menuGroup:insert(background)
    menuGroup:insert(example1)
    menuGroup:insert(example2)
    menuGroup:insert(example3)
    menuGroup:insert(example4)

    example1:addEventListener("touch", changeScene)
    example2:addEventListener("touch", changeScene)
    example3:addEventListener("touch", changeScene)
    example4:addEventListener("touch", changeScene)

    return menuGroup
end