The issue is, I pretty sure, related to access restrictions. It is not allowed to just open a local file. And I can imagine that that is a good thing in general. The current .json is a data file. It is a real .json file in the sense that it contains only data:
{ "$id": "1", "PathChartPoints": { ... }, "PathName": "AIAPNorth" }
Rewriting it to a javascript file should make things easier.
my data = { "$id": "1", "PathChartPoints": { ... }, "PathName": "AIAPNorth" }
It is not as clean. But it might circumvent all kinds of issues with access restrictions and the various ways the browsers deal with it. I will come back to this.
Jeroen.