Card Layout getting an error
===

When the app launches it will display `screen1`. And then when we click on a button it will display `panel1` or `panel2`. My code as follows; I get an error when i add `panel2`.

    launch: function() {

 
		Ext.create('Ext.container.Viewport', {
			layout: 'card',
			items: [
			{ 
				xtype: 'panel', 
            items: { xtype: 'screen1' }
			},
			{
				xtype: 'panel',
				items: { xtype:'panel1' }
			}

			] 
		}); 

}

As soon as i add another panel; and i get an error

    TypeError: namespace is undefined
    [Break On This Error] 	
    
    if (namespace === from || namespace.substring(0, from.length) === from) {
    

Code:

    items: [
    			{ 
    				xtype: 'panel', 
                items: { xtype: 'screen1' }
    			},
    			{
    				xtype: 'panel',
    				items: { xtype:'panel1' }
    			},
    {
    xtype: 'panel',
    				items: { xtype:'panel2' }
    }
    
    			] 

NOTE: I have added the `Panel2` in the  `views: [ Panel2']`