Recent versions of IIS don't serve up .json files by default (you'll see a 404 error in the console)

This can be fixed by adding a new MIME type for .json file to IIS' configuration, as detailed on this stackoverflow post.

Or, if that's not feasible, you could change Adapt so that the JSON data is held in some other format.

Not many people use IIS so this is unlikely to crop up much.