Neither https://playcanvas.com/editor/scene/639774 or https://playcanvas.com/editor/scene/639772 works with the attached script: entity_creator.js, which has been working previously.
I am a great fan of the whole concept, and I want to use it professionally with both a 15$ upgrade now and maybe later with the large upgrade within the multibillion coorperation i work within - 1st things 1st -> make it work 
obt
//br Thomas
Line 92 this.app.root.addChild(entity); is commented out which adds the created entity to the scene graph so it can be rendered.
Uncomment the line.
Ok, and there actually where some more things that I found out when going through it all :-/
(bear with me as I come from the Unity-world, where more debugging tool-functionallity is available - in js-terms: for now I am a little spoiled coding-wise )
Chrome Dev tools are your friend.