No class registered for interface 'mx.styles::IStyleManager2'.

Question

when i run this code in flex3.2
<?xml version="1.0" encoding="utf-8"?>
<mx:VBox xmlns:mx="http://www.adobe.com/2006/mxml" width="400" height="300" creationComplete="init()">
<mx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.co
[Bindable]
private var permissionsXML:XML =
<permissions>
  <permission pId="1" pName="Security Permissions" pParentID="0" checked="0">
  <permission pId="2" pName="User Create" pParentID="1" checked="0"/>
  <permission pId="3" pName="User Edit" pParentID="1" checked="0"/>
  <permission pId="4" pName="User Group Create" pParentID="1" checked="0"/>
  <permission pId="5" pName="User Group Edit" pParentID="1" checked="0">
      <permission pId="48" pName="Edit Group Members" pParentID="5" checked="0"/>
      <permission pId="49" pName="Edit Group Permissions" pParentID="5" checked="0"/>
  </permission>
</permission>
  <permission pId="11" pName="Content Permissions" pParentID="0" checked="0">
      <permission pId="12" pName="Content Create" pParentID="11" checked="0"/>
      <permission pId="13" pName="Content View" pParentID="11" checked="0"/>
      <permission pId="14" pName="Content Edit" pParentID="11" checked="0">
      <permission pId="54" pName="Edit Content Date" pParentID="14" checked="0"/>
      <permission pId="55" pName="Edit Content Creator" pParentID="14" checked="0"/>
      <permission pId="56" pName="Edit Content Status" pParentID="14" checked="0"/>
      <permission pId="58" pName="Edit Content Image" pParentID="14" checked="0"/>
      </permission>
  </permission>
</permissions>
private function save():void{
   //create an XMLList of all 'Permission' nodes whose 'checked'
   //attribute is set to 1...
   var xList:XMLList = permissionsXML.descendants().(@checked == "1");
   var str:String = new String();
   str = "The following permissions are checked.\n";
   //loop through xList and add the 'pDisplayName' attribute
   //to the string...     
   for (var x:uint=0; x < xList.length(); x++){
      str+=xList[x].@pName + "\n"; 
   Alert.show(str);
]]>
</mx:Script>
    <mx:Button label="SAVE" click="save()"/>
    <mx:Tree id="trPermissions" dataProvider="{permissionsXML}"
        itemRenderer="PermissionsTreeItemRendererV2"
        showRoot="false"
        paddingTop="5"
        labelField="@pName"
        height="100%"
        width="300"
        backgroundAlpha="0"
        folderClosedIcon="{null}"
        folderOpenIcon="{null}"
        defaultLeafIcon="{null}"
        />
</mx:VBox>
Tree item renderer:
package
    import mx.controls.treeClasses.TreeItemRenderer;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import mx.controls.CheckBox;
    import mx.controls.treeClasses.*;
    public class PermissionsTreeItemRendererV2 extends TreeItemRenderer{
        public var chk:CheckBox;
        public var itemXml:XML;
        public function PermissionsTreeItemRendererV2(){
            super();
            mouseEnabled = false;
        override public function set data(value:Object):void{
            if(value != null){
                super.data = value;
                this.itemXml = XML(value);
                if(this.itemXml.@checked == "1"){
                    this.chk.selected = true;
                }else{
                    this.chk.selected = false;
        override protected function createChildren():void{
            super.createChildren();
            chk = new CheckBox();
            chk.addEventListener(MouseEvent.CLICK, handleChkClick);
            addChild(chk);
        override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void{
            super.updateDisplayList(unscaledWidth,unscaledHeight);
            if(super.data){
                var tld:TreeListData = TreeListData(super.listData);
                //In some cases you only want a checkbox to appear if an
                //item is a leaf
                //if so, then keep the following block uncommented,
                //otherwise you can comment it out to display the checkbox
                //for branch nodes
                if(tld.hasChildren){
                    this.chk.visible = false;
                }else{
                    //You HAVE to have the else case to set visible to true
                    //even though you'd think the default would be visible
                    //it's an issue with itemrenderers...
                    this.chk.visible = true;
                if(chk.visible){
                    //if the checkbox is visible then
                    //reposition the controls to make room for checkbox
                    this.chk.x = super.label.x
                    super.label.x = this.chk.x + 17;
                    this.chk.y = super.label.y+8;
        private function handleChkClick(evt:MouseEvent):void{
            if(this.chk.selected){
                //this.checked = true;
                this.itemXml.@checked = "1";
            }else{
                //this.checked = false;
                this.itemXml.@checked = "0";

Answer 1

The problem was that I was launching an MXML file that was based on “VBOX” on accident. It wasn’t launching the Application. changed to <mx:application> succesfully works..