Your script code is wrong again.
var vertexShader = this.app.assets.find('vshader');
Why you doing this if you already have attribute.
Then further down, asset != resource.
So what you need is this:
var vertexShader = this.vshader.resource;
Use Dev Tools in Chrome, and
console.log to log things out and inspect variables in code using breakpoints - those are essential skills in development.