Nested element (web component) can't get its template
I made a simple example using Web Components with two custom elements (v1) where one is nested in another. index.html: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Example</title> <meta name="description" content=""> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="import" href="app-container.html"> </head> <body> <app-container></app-container> </body> </html> app-container.html: <link rel="import" href="toolbar.html"> <template id="app-container"> <app-toolbar></app-toolbar> </template> <script> customElements.define('app-container', class