ajax json response from PHP not recognized

ajax json response from PHP not recognized

PHP server:
$result = array(); //declare empty array
$result['error']='';
$result['result']=1;
$result['crud']='E';
echo json_encode($result);
===================================
AJAX
 $.ajax(
      {
        url : "xxxx.php",
        method: "POST",
        data : value,
        dataType : "JSON",
        success: function(response, status, xhr)
        {
          var crudType =  response.crud;
          var dataResult = response.result;
              
          if((crudType == 'E') && (dataResult == 1))
              {
               --  something --
              } else
                  {--  something -- }
        },
        error: function(jqXHR, textStatus, errorThrown)
        {
           alert("Error!");
        }
      });
====================================
response payload:
{"error":"","result":1,"crud":"E"}
====================================

Problem: ajax always says "Error!"...and does not go into the "success" path of code..

What am I doing wrong here ?