问Codenameone BrowserComponent.setProperty给NullPointerException

EN

java.lang.NullPointerException
    at com.codename1.impl.javase.JavaSEPort.setBrowserProperty(JavaSEPort.java:11340)
    at com.codename1.ui.BrowserComponent.setProperty(BrowserComponent.java:607)

import static com.codename1.ui.CN.*;
import com.codename1.ui.Form;
import com.codename1.ui.Dialog;
import com.codename1.ui.plaf.UIManager;
import com.codename1.ui.util.Resources;
import com.codename1.io.Log;
import com.codename1.ui.BrowserComponent;
import com.codename1.ui.Toolbar;
import com.codename1.ui.events.ActionEvent;
import com.codename1.ui.events.ActionListener;
import com.codename1.ui.layouts.BorderLayout;

/**
 * This file was generated by <a href="https://www.codenameone.com/">Codename One</a> for the purpose 
 * of building native mobile applications using Java.
 */
public class MyApplication {

    private Form current;
    private Resources theme;

    public void init(Object context) {
        // use two network threads instead of one
        updateNetworkThreadCount(2);

        theme = UIManager.initFirstTheme("/theme");

        // Enable Toolbar on all Forms by default
        Toolbar.setGlobalToolbar(true);

        // Pro only feature
        Log.bindCrashProtection(true);

        addNetworkErrorListener(err -> {
            // prevent the event from propagating
            err.consume();
            if(err.getError() != null) {
                Log.e(err.getError());
            }
            Log.sendLogAsync();
            Dialog.show("Connection Error", "There was a networking error in the connection to " + err.getConnectionRequest().getUrl(), "OK", null);
        });        
    }

    public void start() {
        if(current != null){
            current.show();
            return;
        }

        BrowserComponent browser = new BrowserComponent();
        browser.addWebEventListener(BrowserComponent.onLoad, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent evt) {

            }
        });
        browser.setProperty("UseWideViewPort", true);
        browser.setProperty("LoadWithOverviewMode", true);
        browser.setProperty("DatabaseEnabled", true);
        browser.setProperty("BuiltInZoomControls", true);
        browser.setProperty("DisplayZoomControls", false);
        browser.setProperty("WebContentsDebuggingEnabled", true);
        browser.setFireCallbacksOnEdt(true);
        browser.setURL("https://www.instagram.com/brianabette/");

        Form hi = new Form("Hi World", new BorderLayout());
        hi.add(BorderLayout.CENTER, browser);
        hi.show();
    }

    public void stop() {
        current = getCurrentForm();
        if(current instanceof Dialog) {
            ((Dialog)current).dispose();
            current = getCurrentForm();
        }
    }

    public void destroy() {
    }

}