uncaught exception: Permission denied to call method XMLHttp

Hello! I have this error: uncaught exception: Permission denied to call method XMLHttpRequest.open. I am using pro_subgrid exemple in my aplication.I don’t know what I missed.
TIA

Such error occurs when you have some code, which loads XML from domain different from domain of main page ( cross-domain security )
By security rules XML documents can be loaded only from the same domain from which main page loaded. If you are using full http paths, then be sure that you are loading page with same domain.