d3.js mailing list.. https://groups.google.com/forum/#!topic/d3-js/MkQsSJDFyms

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.graticule {
      fill: none;
      stroke: #777;
      stroke-opacity: .5;
      stroke-width: .5px;
   }

.land {
      fill: #222;
   }

.boundary {
      fill: none;
      stroke: #fff;
      stroke-width: .5px;
   }

.route {
      fill: none;
      stroke: blue;
      stroke-width: 1px;
   }

</style>
<body>
   <div id="root"></div>
   <script src="https://d3js.org/d3.v3.min.js"></script>
   <script src="https://d3js.org/topojson.v1.min.js"></script>
   <script src="https://d3js.org/queue.v1.min.js"></script>
   <script>
      
var G = (function(d3){

return {
      init : function(){

this.ui = {};

var width = G.ui.width = 960;
         var height = G.ui.height = 770;

var projection = this.ui.projection = d3.geo.mercator()
         .scale((width + 1) / 2 / Math.PI)
         .translate([width / 2, height / 2])
         .precision(.1);

var path = this.ui.path = d3.geo.path()
         .projection(projection);

queue()
         .defer(d3.json, "https://bl.ocks.org/../../data/world-50m.json")
         .await(this.ready);

ready : function(error, world, points, interactions) {

var path = G.ui.path;
         var projection = G.ui.projection;
         var width = G.ui.width;
         var height = G.ui.height;

var svg = G.ui.svg = d3.select("#root").insert("svg", "#instructions")
         .attr("id", "map")
         .attr("width", width)
         .attr("height", height);

var self = this;

var countries = topojson.feature(world, world.objects.countries).features;

// fixed it by changing your "return d" to "return indx" on line 87

// personally, i suggest looping through the dataset, and appending the property code = 1 to
            // every element instead of what we've done below. when we use the second argument in d3,
            // by convention, it's to dictate which key to bind the data to the document, and not to
            // modify the dataset. by modifying the data *before* we bind it, it makes things clear
            // for subsequent readers

svg.selectAll("path:not(.graticule)")
         .data(countries, function(d, indx){
            d.code = "1"; 
            return indx;
         })
         .enter().append("path")
         .attr("d", path);

}
   }
})(d3);

G.init();
      
   </script>
</body>

Modified http://d3js.org/d3.v3.min.js to a secure url

Modified http://d3js.org/topojson.v1.min.js to a secure url

Modified http://d3js.org/queue.v1.min.js to a secure url

Changed /mbostock/raw/4090846/world-50m.json to a local referenece

https://d3js.org/d3.v3.min.js

https://d3js.org/topojson.v1.min.js

https://d3js.org/queue.v1.min.js