WCF / ASMX :: Incoming Message Has An Unexpected Message Format 'Raw'

I am having a wcf service that is throwing this error...here is my code:

this is the javascript calling

this._Proxy = function (serviceURL, serviceParam, dataType, type, data) {
this._URL = serviceURL + encodeURIComponent(serviceParam);
this._DataType = dataType == null || dataType == 'undefined' || dataType == '' ? defaultDataType : dataType;
this._Type = type == null || type == 'undefined' || type == '' ? defaultType : type;
this._Data = data;
this.Invoke = function () {
debugger;
$.ajax({
url: this._URL,
dataType: this._DataType,
type: this._Type,
data: data,
success: function () {
//Do nothing on success
return;
},
}