First of all i have not enough word to thanks the blog owner of (http://adobeflash.wordpress.com) who have included some important information on loacl file loading. The magic line is -use-network=false
You can read the post in this link. I am just adding 2 Flash Builder 4.6 editor image that how you can apply things at your end.
In summary, if you face any error to load local XML file on browser, specially in Google Chrome, you can do following things with your project.
1. Right Click on your project folder from Package Explorer and Select Properties.
2. Add the magic line “ -use-network=false” under Additional Compiler Arguments.
It would seem that this setting has to be made for each project.
Stupid security settings.
:)…..Best of luck with your projects.
Simply Coder 