consider the following piece of QML code:

import QtQuick 2.13
import QtQuick.Window 2.13
import QtQuick.Scene3D 2.0

import Qt3D.Render 2.0

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
}

Running this piece of code results in a runtime error:

qrc:/main.qml:9 Only for assigning window surface property

The reason is that Qt3DQuick3DRenderPlugin registers an uncreatable type also named window, although it is just an internal wrapper of QWindow.

(See https://code.woboq.org/qt5/qt3d/src/quick3d/imports/render/qt3dquick3drenderplugin.cpp.html Line 164.)

While it is possible to import QtQuick.Windows using an alias, e.g.
import QtQuick.Window 2.13 as W and then use W.Window { ....
this should not be neccessary for a number of reasons:

1. Only standard Qt modules are used. There should be no nameclashes within a single product.
2. There is no apparent reason why the internal type uses the same name as the publicly documented class Window
3. The error message is not helpfull without looking into the sourcecode

This is a follow up to https://forum.qt.io/topic/105826/nameclash-between-qtquick-window-and-qt3d-window/5