I downloaded a recent Fiddle, and the Ext version in index.html was 4.2.3 and not 5.1.0, which is what I see when it runs in Sencha Fiddle. My Fiddle is http://ift.tt/1APMLVS, and I clicked the button to the left of the run button, whose tooltip says "Download Fiddle (zip)."

I had switched Ext versions a couple times to see what effect that would have, but the most recently saved version uses 5.1.0.