Occasionally errors with: Module http://localhost:52404/AppTS/Main.js interpreted as amd module format, but called System.register.

config.js

System.config({
  baseURL: "/",
  defaultJSExtensions: true,
  transpiler: "typescript",
  paths: {
  	"*": "AppTS/*",
    "npm:*": "jspm_packages/npm/*"
  },
  meta: { '/AppTS/*': { scriptLoad: true } },
  map: {
    "typescript": "npm:typescript@1.7.3"
  },
});

Main.js

System.register([], function(exports_1) {
    var WorldSelection;
    return {
        setters:[],
        execute: function() {
            WorldSelection = (function () {
                function WorldSelection() {
                    alert("Typescript works with systemjs");
                }
                WorldSelection.prototype.activate = function () {
                    alert("Typescript works with systemjs in activate");
                };
                return WorldSelection;
            })();
            exports_1("WorldSelection", WorldSelection);
        }
    }
});
//# sourceMappingURL=Main.js.map

Main.ts

export class WorldSelection 
{
    constructor()
    {
        alert("Typescript works with systemjs");
    }

    activate()
    {
        alert("Typescript works with systemjs in activate");
    }
}