RunTimeHelpers:covertToObject() is asserting on Q_ASSERT(value.isString()) during a setSource on a QQuickWidget

    switch (value.type()) {
...
    <SNIP>
...
    case Value::Managed_Type:
        Q_ASSERT(value.isString());
        return engine->newStringObject(value);

 	Qt5Cored.dll!qt_message_fatal(QtMsgType __formal, const QMessageLogContext & context, const QString & message) Line 1568	C++
 	Qt5Cored.dll!QMessageLogger::fatal(const char * msg, ...) Line 777	C++
 	Qt5Cored.dll!qt_assert(const char * assertion, const char * file, int line) Line 2895	C++
>	Qt5Qmld.dll!QV4::RuntimeHelpers::convertToObject(QV4::ExecutionEngine * engine, const QV4::Value & value) Line 439	C++
 	Qt5Qmld.dll!QV4::Runtime::getProperty(QV4::ExecutionEngine * engine, const QV4::Value & object, int nameIndex) Line 679	C++
 	0000005d15700f4e()	Unknown
 	0000005d12c7b900()	Unknown
 	0000005d13da13c0()	Unknown
 	0000005d00000083()	Unknown
 	Qt5Qmld.dll!QV4::Debugging::DebuggerBreakPoint::~DebuggerBreakPoint(void)	Unknown
 	0000005d13da13a0()	Unknown
 	Qt5Qmld.dll!QV4::Scope::alloc(int nValues) Line 91	C++

ColumnLayout{
    Label {
    ...
    }
    TextField {
    ...
    }
}

ColumnLayout{
    Label {
    ...
    }
    TextInput {
    ...
    }
}