If you are referring to the Container Skin, its just a stock skin
template with the color changed to black. Remove the button and the
error does not happen and the app runs fine with nice black area, semi
transparent.
<?xml version="1.0" encoding="utf-8"?>
<!--
ADOBE SYSTEMS INCORPORATED
Copyright 2008 Adobe Systems Incorporated
All Rights Reserved.
NOTICE: Adobe permits you to use, modify, and distribute this file
in accordance with the terms of the license agreement accompanying it.
-->
<!--- The default skin class for a Spark SkinnableContainer container.
@see spark.components.SkinnableContainer
@langversion 3.0
@playerversion Flash 10
@playerversion AIR 1.5
@productversion Flex 4
-->
<s:Skin xmlns:fx="http://ns.adobe.com/mxml/2009";
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:fb="http://ns.adobe.com/flashbuilder/2009"; alpha.disabled="0.5">
<fx:Metadata>
<![CDATA[
/**
* @copy spark.skins.spark.ApplicationSkin#hostComponent
*/
[HostComponent("spark.components.SkinnableContainer")]
]]>
</fx:Metadata>
<s:states>
<s:State name="normal" />
<s:State name="disabled" />
</s:states>
<!--- Defines the appearance of the SkinnableContainer class's
background. -->
<s:Rect id="background" left="0" right="0" top="0" bottom="0">
<s:fill>
<!--- @private -->
<s:SolidColor id="bgFill" color="#000000" alpha=".5"/>
</s:fill>
</s:Rect>
<!--
Note: setting the minimum size to 0 here so that changes to the
host component's
size will not be thwarted by this skin part's minimum size.
This is a compromise,
more about it here: http://bugs.adobe.com/jira/browse/SDK-21143
-->
<!--- @copy spark.components.SkinnableContainer#contentGroup -->
<s:Group id="contentGroup" left="0" right="0" top="0" bottom="0"
minWidth="0" minHeight="0">
<s:layout>
<s:BasicLayout/>
</s:layout>
</s:Group>
</s:Skin>
