Custom Widget is not appearing in widgets list in xCP Designer

I have a widget which I have developed for using in xCP Designer and to be dropped onto the interface pages. It is a bare bones one because I just want it get it worker before I tackle anything more complex.

The following is the JavaScript

Ext.define("stg.widgets.demographics", {

    extend: 'Ext.Component',

    alias: 'widgets.demographics',

initComponent : function() {

    }

});

I can't see any error in the javascript

and the corresponding config file

<?xml version="1.0" encoding="UTF-8"?>
<widget xmlns="http://documentum.emc.com/2010/UI-Model" xmlns:xcp="http://documentum.emc.com/xcp/2010"
        id="demographics" xtype="demographics"
        version="1.0.0000.001">

    <name>Patient Demographics</name>
    <description>Display Patient Demographics.</description>
    <author email="paul.chapman@stgeorges.nhs.uk">Joseph Wong</author>

    <icon src="icons/person_24_wig.png" width="24" height="24"/>
<icon src="icons/person_wig.png" width="16" height="16"/>

    <content src="content/stg/widgets/demographics.js" type="text/javascript"/>
    <content src="content/stg/widgets/designer/demographics.js" type="text/javascript" nls="stg/widgets/designer/demographics.js" mode="design"/>

    <category>xcpPalette:Custom</category>

    <configuration> 
    </configuration>

</widget>

Again I cannot see any error in the XML - the lack of properties is deliberate as I was thinking of adding some once the widget appears.

JAR file is attached.

However even though it imports without any error into the Application Model it does not appear within the interface designer in xCP, can anyone see a reason why? xCP Version is Build: 2.0.0070.5035)

Thanks in advance

Thanks in advance