title: React <div> cannot appear as a child of <tr> Warning
body: <p>I am getting the following warnings in a React component:</p>
  
  <p><a href="https://i.stack.imgur.com/jd28v.png" rel="noreferrer"><img src="https://i.stack.imgur.com/jd28v.png" alt="enter image description here"></a></p>
  
  <p>The related code is the following:</p>
  
  <pre><code>import React, { PropTypes } from 'react';
  import { Checkbox } from 'react-bootstrap'; 
  
  const MyComponent = (params) =&gt; {
  
  function onSelect(event) {
      params.onSelect(event, params.data.id);
  }
  
  return (
      &lt;tr key={params.data.id}&gt;
          {params.isSelectable ? (
              &lt;Checkbox onChange={onSelect}&gt;
                  &lt;td&gt;{params.data.firstName}&amp;nbsp;&lt;/td&gt;
                  &lt;td&gt;{params.data.lastName}&amp;nbsp;&lt;/td&gt;
              &lt;/Checkbox&gt;
          ) : (
              &lt;div&gt;
                  &lt;td&gt;{params.data.firstName}&amp;nbsp;&lt;/td&gt;
                  &lt;td&gt;{params.data.lastName}&amp;nbsp;&lt;/td&gt;
              &lt;/div&gt;
          )}
      &lt;/tr&gt;
  );
  </code></pre>
  
  <p>};</p>
  
  <p>If I remove the div tags, I get the following error:</p>
  
  <blockquote>
    <p>Adjacent JSX elements must be wrapped in an enclosing tag</p>
  </blockquote>
  
  <p>I am new to React, so i am not quite clear on what is going on here. What's the problem and how can I fix it?</p>
  
  <p>Update: my React version is 15.3.2.</p>