502 Bad Gateway: Registered endpoint failed to handle the request.

all the app apis work fine on the local machines, but after pushed to cloud foundry all the api return 502 Bad Gateway: Registered endpoint failed to handle the request.

app is built on Node.js use the javascript to call the local json file and Express api, some of the code call json files as below:

function get_json(){ $.ajax({ dataType: "json", url: 'json/export.json', success: parse_json }); }

 $http.get('json/risk_file.json')
     .success(function(data) {
         $scope.webData = data;
         console.log(data);
     })
     .error(function(error) {
         console.log('Error: ' + error);
     });