Problem embedding Qt3DWIndow using createWindowContainer in a MainWindow

p.f.f.

Hi Everybody,
I would like to use Qt3D in one of my projects but I am a bit stuck with stability problems.
The compiler I am using is MSVC2015 64 bit and I have tried Qt 5.8.0 and 5.9.0 beta and I have different errors when compiling a simple application in which I have embedded a 3D widget using this code in the MainWIndow constructor generated by QtCreator for an application managed by QtDesigner:

ui->setupUi(this);
    window3d=new Qt3DExtras::Qt3DWindow();
    ui->tab->layout()->addWidget(QWidget::createWindowContainer(window3d));

I have added no additional code.
The application crashes randomly mostly when closing it and without any message in Qt 5.8.0 and ,I have the compile-time error "QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined" with Qt 5.9.0 beta.

This happens both in debug an release mode.

Any hint on how to "stabilize" my application or of what am I doing wrong?

Thanks in advance for your help,

Pier