title: Getting error "Strict MIME type checking is enforced for module scripts per HTML spec" when trying to import project
body: <p>Trying to create some reusable components for our Electron screen using <code>lit-html</code>. When I attempt to add an example component I run into an error. </p>
  
  <p>Using <code>electron: ^5.0.6</code></p>
  
  <p>Trying to import module <code>my-element.js</code> (most of this code is example code and I'm just trying to get it working)</p>
  
  <pre><code>&lt;head&gt;
      &lt;!-- Polyfills only needed for Firefox and Edge. --&gt;
      &lt;script src="https://unpkg.com/@webcomponents/webcomponentsjs@latest/webcomponents-loader.js"&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;!-- Works only on browsers that support Javascript modules like
       Chrome, Safari, Firefox 60, Edge 17 --&gt;
  &lt;script type="module" src="my-element.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>The module <code>my-element.js</code> contains the following:</p>
  
  <pre><code>import {LitElement, html, css} from 'lit-html';
  
  class MyElement extends LitElement {
  
    static get properties() {
      return {
        mood: {type: String}
      }
    }
  
    static get styles() {
      return css`.mood { color: green; }`;
    }
  
    render() {
      return html`Web Components are &lt;span class="mood"&gt;${this.mood}&lt;/span&gt;!`;
    }
  }
  
  customElements.define('my-element', MyElement);
  </code></pre>
  
  <p>When the page loads I get an error</p>
  
  <pre><code>Failed to load module script: The server responded with a non-JavaScript MIME type of "". Strict MIME type checking is enforced for module scripts per HTML spec.
  </code></pre>
  
  <p>I have tried different ways of importing <code>lit-html</code> but nothing has solved the error.</p>
  
  <p>Ex. <code>import {LitElement, html, css} from '../../node_modules/lit-html/lit-html';</code></p>
  
  <p>Ex. <code>import {LitElement, html, css} from '../../node_modules/lit-html/lit-html.js';</code></p>