filesystembrowser QML example

[GrahamLa]

Hi
I am using the filesystembrowser QML example and I can build and execute it.
However when it is running the following messages are output

Model size of -84 is less than 0
"Could not convert argument 2 at"
	 "expression for index@file:///C:/Qt/5.12.2/mingw73_32/qml/QtQuick/Controls/Private/TreeViewItemDelegateLoader.qml:84"
	 "expression for onCompleted@file:///C:/Qt/5.12.2/mingw73_32/qml/QtQuick/Controls/Private/BasicTableView.qml:546"
"Passing incompatible arguments to C++ functions from JavaScript is dangerous and deprecated."
"This will throw a JavaScript TypeError in future releases of Qt!"

There are many such messages - What do they mean and can I solve them?

Thanks