Error when calling node.js from client side using $.ajax

I'm trying to make an Ajax call from my client like that:

 $.ajax({
        url: '/item/' + id + '/action?parameter=' + parameter,
        method: 'GET',
        success: function(data) {
          .....

        }
});

and the error I'm getting is:

500 (Internal Server Error) (from the Azure server (c["X-Requested-With"]="XMLHttpRequest");for(e in c)void 0!==c[e]&&f.setRequestHeader(e,c[e]+""); (highlight)

The rest of the site is working well, only the ajax call returs the error (tried also with POST)

In my server, I've done few attempts:
1)

cors = require('cors'),
path = require('path');
var app = express();
app.use(cors());

2)

exports.action= function(req, res) {

res.setHeader("Access-Control-Allow-Origin", "*");
res.setHeader("Access-Control-Allow-Headers", "X-Requested-With");

But still getting the error