The DrawHelper he a (seemingly unmaintained) plug-in and not something the Cesium team itself works on (though I’m sure if you were to update it the author would accept pull requests). There are no official tools available (yet) for drawing/editing graphics with Cesium.
As for your callstack, it’s useless because you are developing against the combined/minified version of Cesium which has very little error checking (for performance reasons) and as you can see, nonsensical variable names (for size/minification reasons). Change your app to use “Build\CesiumUnminified” instead of “Build\Cesium” during development and you’ll get much better error checking and informative errors.