About KmlLayer URL Problem

[daewoongkim]

I'm testing add to KMLLayer in flex4.0
I confirmed Basic KmlLayer sample in ArcGis Resources.

Sample code about KMLLayer part
<esri:KMLLayer id="lower48Reflectivity" name="Lower 48 Reflectivity"
     load="lower48Reflectivity_loadHandler(event)"
     loadError="lower48Reflectivity_loadErrorHandler(event)"
     url="http://dl.dropbox.com/u/62421751/RIDGE_NationalLower48Reflectivity.kmz"/>

this code operate very well !!

but url change to http://localhost:6766/KMLFILE/filename.kml, I can see Alert dialog "File not found, Wrong URL"

this url correct!!!

I confirmed this kml file through web browser as IE or Chrome, but flex builder 4.0 show Alert dialog to me.

what is problem??  security??

I don't know and understand why occur this problem.

please help me T^T

[DasaPaddock]

The url needs to be publicly accessible to the Internet since the KMLLayer uses a service on ArcGIS.com to translate the KML to JSON.