I need one urgent help.
I am following MVC architecture and i have implemented grid panel with paging toolbar as docked item.
Ext.define('DEMO.view.grid.GridPage' ,{
extend: 'Ext.grid.Panel',
alias : 'widget.GridPage',
title : 'Country',
store: 'GridStore',
width: 400,
height: 225,
columns: [
{header: "Country Code", width: 100, dataIndex: 'countryCode', sortable: true},
{header: "Country Name", width: 100, dataIndex: 'countryName', sortable: true}
dockedItems: [{
xtype: 'pagingtoolbar',
store: 'GridStore', // same store GridPanel is using
dock: 'bottom',
displayInfo: true
initComponent: function() {

I have a viewport and in west panel, i have added menu, and on click of the menu the grid page is loaded, and everything works fine. but when i click the menu again for the second time i get an exception:

uncaught exception: [Exception... "Component returned failure code: 0x80004003 (NS_ERROR_INVALID_POINTER) [nsIDOMHTMLDivElement.insertBefore]" nsresult: "0x80004003 (NS_ERROR_INVALID_POINTER)" location: "JS frame :: http://localhost:8080/springExtFrame...t-all-debug.js :: <TOP_LEVEL> :: line 15681" data: no]

Please help.