Proper namespace in root application tag Flashbuilder 4

Question

In my Upgrade application to FB 4.
  if I want to just support the existing halo mx namespace in my components what do I need to do?
If I use the following
<mx:Application xmlns:mx="library://ns.adobe.com/flex/mx" xmlns:local="*"
                layout="absolute"
                historyManagementEnabled="false">
<mx:Application>
I get unable to resolve MXML language version. Please specify language namespace on the root document tag
However if I keep <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
                       layout="absolute"
                        historyManagementEnabled="false">
<mx:Application>
When I revert back to above and go over any of my the mx controls with cntrl space nothing shows
and one of my shared components also tells me the style "borderThickness" is only supported with the
theme "halo"
Any ideas?
Thanks, Mike

Answer 1

Got a similar problem here.
I dont want to use the new Namespace here. So i keep my code as is ans use compatibility 3.5 as an option to the compiler.
I get this error, any ideas?
[info] C:\ir\workspace\SaphirTrunk\mod\commun\ir-mod-commun-flex-test\target\CommunFlexTestModul eMain.mxml: Error: Unable to resolve MXML language version. Please specify the language namespace on the root document tag.
Code:
<?xml version="1.0" encoding="utf-8"?>
<module:Module
        xmlns:mx="http://www.adobe.com/2006/mxml"
        xmlns:ssq="http://www.ssq.ca/ir/xml/mxml"
        xmlns:module="ca.ssq.ir.puremvc.module.*"            
        width="0" height="0">
    <!--
   Only for tests purpose
    -->
</module:Module>