Outlook addin keep quitting when loading java applet using webbrowsercontrol

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C#3.5

64-bit

Outlook

AddIn

My x64 Outlook Addin got some problem when loading java applet. In My Outlook AddIn, I use webBrowerControl to load java applet. I tested in windows7 x64 and MS Outlook 2010 x64. There is no issue at all. But the problem is started when I went to customer side and install. When webBrowsercontrol load the java applet, the whole outlook is crash and exit. Is there any setting that cause the this problem? the client environment used windows7 x64 and MS Outlook2010 x64. they have both x64 and x32 java 7 update 42.

Here is the source that cause the problem

private void Form3_Load(object sender, EventArgs e)
    {
        try
        {
            this.Refresh();

            String APPLETCHK_URL = System.Configuration.ConfigurationManager.AppSettings["ELMS_APPLETCHK_URL"];
            APPLETCHK_URL = SERVERURL + APPLETCHK_URL;                
            logger.Debug("Downloading Applet from " + APPLETCHK_URL);
            this.webBrowser1.Url = new System.Uri(APPLETCHK_URL);                
            logger.Debug("Downloading completed.");
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

error caused in the following line.

this.webBrowser1.Url = new System.Uri(APPLETCHK_URL); 

Thanks

What I have tried:

Developing Outlook AddIn x64. At testing environment , it is working. but at client machine, it is keep quitting the Outlook.