handle non-200 status codes

www/common/common-util.js

@@ -101,11 +101,11 @@ define([], function () {
         xhr.open("GET", src, true);
         xhr.responseType = "arraybuffer";
         xhr.onload = function () {
+            if (this.status !== 200) {
+                return CB('XHR_ERROR');
+            }
             return void CB(void 0, new Uint8Array(xhr.response));
         };
-        xhr.onerror = function () {
-            CB('XHR_ERROR');
-        };
         xhr.send(null);
     };