Error building Player: Exception: java Failed: ... C:\...\flex-config.xml

Hi,

I'm a beginner in unity environment, and I have a exporting problem, so please bare with me, thanks
So here is my problem :
when I try to export for flash in Unity, even thought when I created a completely new project,
with an empty scene (only a camera there), I always get these two errors :

Os win7 | Unity 4 | Flash player - updated | JRE - installed |
- or may be do I need a flex plu-gin ?..

I've allso posted this here : http://forum.unity3d.com/threads/13...Unity-SWF-Content/page2?p=1418941#post1418941
Thanks