Ajax加载程序冻结

My ajax loader freezes the browser and throws an JavaScript error (stop script or continue). I tried changing async to true/false but no luck. I'm creating div tables on success.

$.ajax({
          type: "POST",
          url: "getschedules",
          data: '{"StartingDate": "' + startdate + '", "EndingDate": "' + enddate + '"}',                   
          contentType: "application/json; charset=utf-8",
          async: true,
          dataType: "json"
          }).done(function (response) {
          adc.createTable(response);
          }).fail(function () {
          })
        }