Why am I getting a Security error in the preview tab of the Application Builder 3.6?

[JoshWhite]

I keep getting an error when viewing the preview in the Application Builder 3.6. 

The error states:

LayerName layer failed to load: Fault code: Channel.Security.Error

Fault info: Security error accessing url

Fault details: Destination: DefaultHTTP

My layers are all pointed to an external ip address and going to the a browser and pulling up the application using the external ip, everything works fine.  If you use the internal address http://servername/flexviewers/appname you also get the security error.  None of my existing layers have any security enabled on them that I am aware of, what could be causing this?

[RobertScheitlin__GISP · Accepted solution]

Josh,

   Do you have a crossdomain.xml file setup on your web server and ArcGIS Server if they are not on the same machine?

[JoshWhite]

They are on the same machine.  There is a crossdomain file that perhaps is not configured correctly.  In fact I found a default crossdomain file and saved it, and now the problem is gone.