Ошибка в QWebView JavaScript error: Requested keys of a value that is not an object.

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QWebView>
#include <QLineEdit>
#include <QPushButton>
class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = 0);
    QWebView* web;
    QLineEdit* line;
public slots:
    void Go_Link();

};
#endif // WIDGET_H

#include "widget.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
Widget::Widget(QWidget *parent) :
    QWidget(parent)
{
    line=new QLineEdit();
    QPushButton* button = new QPushButton("Поиск");
    web=new QWebView;
    QHBoxLayout* box = new QHBoxLayout;
    box->addWidget(line);
    box->addWidget(button);
    connect(button,SIGNAL(clicked()),this,SLOT(Go_Link()));
    QVBoxLayout* box1 = new QVBoxLayout;
    box1->addLayout(box);
    box1->addWidget(web);
    setLayout(box1);
}
void Widget::Go_Link(){
    web->load(QUrl(line->text()));
}