The code

``` javascript
class Comp extends React.Component {
  componentWillMount() {
    setTimeout(() => {
      this.setState({});
    });
  }

  render() {
    return <div onClick={() => {}} />;
  }
}

ReactDOMServer.renderToString(<Comp />);
```

produces errors:

> Warning: React can't find the root component node for data-reactid value `.0`. If you're seeing this message, it probably means that you've loaded two copies of React on the page. At this time, only a single copy of React can be loaded at a time.
> 
> Uncaught TypeError: Cannot read property 'firstChild' of undefined

But if I remove `onClick` handler the errors go away...

See demo: http://codepen.io/dened/pen/YyByYr

return Object.assign({}, currentContext, childContext);
    }
    return currentContext;
  },
  /**
   * Assert that the context types are valid
   *
   * @param {object} typeSpecs Map of context field to a ReactPropType
   * @param {object} values Runtime values that need to be type-checked
   * @param {string} location e.g. "prop", "context", "child context"
   * @private
   */
  _checkContextTypes: function(typeSpecs, values, location) {
    checkReactTypeSpec(
      typeSpecs,
      values,
      location,
      this.getName(),
      null,
      this._debugID
    );
  },
  receiveComponent: function(nextElement, transaction, nextContext) {
    var prevElement = this._currentElement;
    var prevContext = this._context;
    this._pendingElement = null;
    this.updateComponent(
      transaction,
      prevElement,
      nextElement,