title: Error: Minified React error #130
body: <p>I have the following ReactJs component in file ./MyInput.react.js</p>
  
  <pre><code>import React from 'react';
  
  export default class MyInput extends React.Component {
    constructor(props) {
      super(props);
      this.id = getNextId();
  
      this.onChange = this.onChange.bind(this);
    }
    onChange(e) {
      this.props.onChange(e.target.value);
    }
    render() {
      return (
        &lt;label htmlFor={this.id}&gt;
          {this.props.label}      
          &lt;input
            id={this.id}
            value={this.props.value} 
            onChange={this.onChange}
            /&gt;
        &lt;/label&gt;
      );
    }
  }
  </code></pre>
  
  <p>Now I try to import it into ./index.js like this:</p>
  
  <pre><code>import {MyInput} from './MyInput.react';
  </code></pre>
  
  <p>The console return me the error:</p>
  
  <pre><code>Error: Minified React error #130
  </code></pre>
  
  <p>The full text of the error you just encountered is:</p>
  
  <pre><code>Element type is invalid: expected a string (for built-in components) or 
  a class/function (for composite components) but got: undefined.
  </code></pre>
  
  <p>What is wrong with that?</p>