After upgrading of Qt from 5.9.0 to 5.9.1, I always got following importunate debugginng message:

QMetaProperty::read: Unable to handle unregistered datatype 'const QQuickPointerDevice*' for property 'QQuickPointerEvent::device'

these messages can be much count in process of lifetime of an application, they appear every time when e.g. any Item is loaded through Loader.

I have attached a simple example project.

PS: this happens only if I try to run the application via "Start Debugging" button from QtC.