Using Polymer Elements in Angular CLI Webpack Applications

Followed instructions letter by letter at https://vaadin.com/docs/-/part/elements/angular2-polymer/ng-cli-webpack.html.
Everything worked up to "...replace the line "main": "main.ts", with "main": "main-polymer.ts",. Now you can run ng serve,..." and all I get is a red "Error" (one-word) message.

​What could the issue be? I'm on npm 3.10.6 and node 4.4.7 with latest angular-cli.

Could someone please respond to this simple enquiry? The miimum expectation is at least your code should work as presented on your website, especially for someone trying to come up to speed on your software. And if there is some dependency I need, kindly disclose.

Thanks!