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

}
    }
    if (__DEV__) {
      if (this._debugID) {
        var callback = (component) => ReactInstrumentation.debugTool.onComponentHasMounted(this._debugID);
        transaction.getReactMountReady().enqueue(callback, this);
      }
    }
    return markup;
  },
  _constructComponent: function(publicProps, publicContext) {
    if (__DEV__) {
      ReactCurrentOwner.current = this;
      try {
        return this._constructComponentWithoutOwner(publicProps, publicContext);
      } finally {
        ReactCurrentOwner.current = null;
      }
    } else {
      return this._constructComponentWithoutOwner(publicProps, publicContext);
    }
  },
  _constructComponentWithoutOwner: function(publicProps, publicContext) {
    var Component = this._currentElement.type;
    var instanceOrElement;
    if (shouldConstruct(Component)) {
      if (__DEV__) {
        if (this._debugID !== 0) {
          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
            this._debugID,