WebView callback/ Java crash

After adding this code, Java Crashes
<pre>
                browser.getEngine().getLoadWorker().stateProperty().addListener( new ChangeListener<Worker.State>() {
                    public void changed(ObservableValue<? extends Worker.State> p, Worker.State oldState, Worker.State newState) {
                        if (newState == Worker.State.SUCCEEDED) {
                            JSObject win = (JSObject) browser.getEngine().executeScript("window");
                            win.setMember("javacallback", listener);
                        }
                    }
                });
</pre>

On the version 7u10 everything works fine

Netbeans project
https://drive.google.com/folderview?id=0Bz7309sTKJ2nanBCdUdwd3R4Tzg&usp=sharing