Nikolai Mavrenkov already created a good description of the problem on Stack Overflow: http://stackoverflow.com/questions/36893449/textarea-placeholder-isnt-shown-in-ie-11-being-rendered-using-react

I just can confirm it breaks in IE11, but works in IE10 (and other browsers) with React v15.0.2.

);
        if (Array.isArray(children)) {
          invariant(
            children.length <= 1,
            '<textarea> can only have at most one child.'
          );
          children = children[0];
        }
        defaultValue = '' + children;
      }
      if (defaultValue == null) {
        defaultValue = '';
      }
      initialValue = defaultValue;
    }
    inst._wrapperState = {
      initialValue: '' + initialValue,
      listeners: null,
      onChange: _handleChange.bind(inst),
    };
  },
  updateWrapper: function(inst) {
    var props = inst._currentElement.props;
    var node = ReactDOMComponentTree.getNodeFromInstance(inst);
    var value = props.value;
    if (value != null) {
      
      
      var newValue = '' + value;