JQuery ajax ($.ajax()) returning to error function despite success (200 ok) response

Turns out that returning void from (asp.net mvc) server function, but jquery ajax call data type was set to json – so when receiving no data back – the ajax function returns to the error function.

So the example below would always alert “error” as the server controller action return was void

$.ajax({type: “POST”,url: “/MyController/MyAction/”,data: [postData], success: function (data) { alert(“success”); }, error: function () { alert(“error”); } });