Private Sub btn_start_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles btn_start.Click
 
        trd1 = New Thread(AddressOf ThreadTask)
        trd1.Start()
 
End Sub

Dim GeckoWebBrowser1 As GeckoWebBrowser
Private Sub ThreadTask()
 
        GeckoWebBrowser1 = New GeckoWebBrowser
        If Me.InvokeRequired Then
           Me.Invoke(Sub() ThreadTask())
           Return
        End If
        Dim ProfileDirectory As String = My.Application.Info.DirectoryPath & _
          "\xulrunner\GeckoFX_cache\" & random_path() & "\"
 
        If Not Directory.Exists(ProfileDirectory) Then
            Directory.CreateDirectory(ProfileDirectory)
        End If
        Xpcom.ProfileDirectory = ProfileDirectory
 
        Dim xrPath As String = _
          System.Reflection.Assembly.GetExecutingAssembly.Location
        xrPath = My.Application.Info.DirectoryPath & "\xulrunner"
 
        Xpcom.Initialize(xrPath)
 
        GeckoWebBrowser1.Location = New System.Drawing.Point(198, 38)
        GeckoWebBrowser1.Name = "GeckoWebBrowser1"
        GeckoWebBrowser1.Size = New System.Drawing.Size(1371, 824)
        GeckoWebBrowser1.TabIndex = 4
        GeckoWebBrowser1.UseHttpActivityObserver = False
        Me.Controls.Add(GeckoWebBrowser1)
        Me.Refresh()
        GeckoWebBrowser1.Navigate("http://google.com/")
 
End Sub

Private Sub btn_ende_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles btn_ende.Click
        beende_geckofx(GeckoWebBrowser1)
End Sub

Sub beende_geckofx(ByVal GeckoWebBrowser1)
 
        GeckoWebBrowser1.Dispose()
        GeckoWebBrowser1 = Nothing
        Xpcom.Shutdown()
        trd1.Abort()
 
End Sub

Xpcom.Initialize(xrPath)
 
System.AccessViolationException wurde nicht von Benutzercode behandelt.
HResult=-2147467261
Message=Attempted to read or write protected memory. This is often an _
  indication that other memory is corrupt.
InnerException: