RTE on RTE

[jude]

I'm getting a run time error on the experimental rich text editor. I've
made a simple test case and pasted the code
<https://gist.github.com/monkeypunch3/a218dca6a9d02b5221519b8b0f66865b> and
error here. I'm using 4.15.

&lt;?xml version="1.0" encoding="utf-8"?>
&lt;s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009";
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx"
                       xmlns:ns="http://flex.apache.org/experimental/ns";
                       >

    &lt;ns:RichTextEditor verticalCenter="0" horizontalCenter="0"
width="300" height="300"/>

&lt;/s:WindowedApplication>

Error:

TypeError: Error #1034: Type Coercion failed: cannot convert
flash.events::Event@25e81737bbc9 to mx.events.FlexEvent.
    at flash.events::EventDispatcher/dispatchEventFunction()