Ajax request returns 200 OK, but an error event is fired instead of success

Question

I have implemented an Ajax request on my website, and I am calling the endpoint from a webpage. It always returns 200 OK, but jQuery execut

Answer 1

Your script demands a return in JSON data type.

Try this:

private string test() {
  JavaScriptSerializer js = new JavaScriptSerializer();
 return js.Serialize("hello world");
}

Answer 2

Another thing that messed things up for me was using localhost instead of 127.0.0.1 or vice versa. Apparently, JavaScript can't handle requests from one to the other.

Answer 3

I had the same problem. It was because my JSON response contains some special characters and the server file was not encoded with UTF-8, so the Ajax call considered that this was not a valid JSON response.

Answer 4

This is just for the record since I bumped into this post when looking for a solution to my problem which was similar to the OP's.

In my case my jQuery Ajax request was prevented from succeeding due to same-origin policy in Chrome. All was resolved when I modified my server (Node.js) to do:

response.writeHead(200,
          {
            "Content-Type": "application/json",
            "Access-Control-Allow-Origin": "http://localhost:8080"
        });

It literally cost me an hour of banging my head against the wall. I am feeling stupid...