Charts: Chart works in fiddle but not in application

Hej

A simple chart I made works fine in fiddle (see here) but will not run in my application. the error I can see in Chrome Developer Tools is:

Uncaught TypeError: Cannot read property 'get' of undefined at ext-all.js:19

I included ext-charts.js and even Cartesian.js to see if this will help, but no cigar.

HTML Code:

<script type="text/javascript" src="Components/Sencha/ext-all.js"></script>
<script type="text/javascript" src="Components/Sencha/packages/ext-charts/build/ext-charts.js"></script>
<script type="text/javascript" src="Components/Sencha/packages/ext-charts/src/chart/series/Cartesian.js"></script>

Why is this happening?

Thanks

Charts: Chart works in fiddle but not in application