Build QDS in Debug mode
Adding a missing import will cause a respective QML type known to the model and go into an inconsistent state as some of the properties are now parsed as bindings that were not before. 

Example:

import QtQuick

Rectangle {
    id: myRect
    property color testcustom: "#acacac"
    width: 675
    height: 636

    Button {
        id: button
        width: 120
        height: 40
        text: "Test"
        anchors.centerIn: parent
    }
}

Consider the code above. The type Button is unknown to model as "import QtQuick.Controls" is missing.
Now add the import i.e. components > + > "QtQuick.Controls"

QDS should crash because of assertions at ModelValidator::shouldBeBindingProperty(...)