I am desperately trying to get a local build of a site to get a JSON file (also local) with no luck. The exact code worked perfect on my server, but once local, breaks.
XmlHttpRequest isn't allowed cross-domain.
If you need to do a demonstration on a local pc, setup your web app to run on local webserver, and have the json source be returned be the same web application.
That's the only way I can think to make it work. You can't use Ajax calls on filesystem for security reasons.