Crash when showing tooltip in an ApplicationWindow via attached show() function

import QtQuick 2.6
import QtQuick.Layouts 1.3
import QtQuick.Controls 2.0
import Qt.labs.folderlistmodel 2.1

ApplicationWindow {
    id: window
    title: "Qt Quick Controls 2 - Material Snippets"
    visible: true

    ToolTip {
        id: saveResultToolTip
    }

    footer: ToolBar {
        RowLayout {
            anchors.fill: parent

            ToolButton {
                text: "Take Screenshot"
                focusPolicy: Qt.NoFocus
                onClicked: saveResultToolTip.ToolTip.show("Boop", 3000);
//                onClicked: saveResultToolTip.open()
            }
        }
    }
}