This usually means that the user mixed up our lowercase/uppercase naming convention; see https://github.com/facebook/react/pull/3429#issuecomment-85166440.

We could add a message like

> Warning: The tag <commentBox> is unrecognized in this browser. If you meant to render a React component, start its name with an uppercase letter.

We'd check this only once per tag and only in development mode.

var node = getNode(this);
  node.onclick = emptyFunction;
}
function trapBubbledEventsLocal() {
  var inst = this;
  
  
  invariant(inst._rootNodeID, 'Must be mounted to trap events');
  var node = getNode(inst);
  invariant(node, 'trapBubbledEvent(...): Requires node to be rendered.');
  switch (inst._tag) {
    case 'iframe':
    case 'object':
      inst._wrapperState.listeners = [
        ReactBrowserEventEmitter.trapBubbledEvent('topLoad', 'load', node),
      ];
      break;
    case 'video':
    case 'audio':
      inst._wrapperState.listeners = [];