title: Array of object is always null in MVC core controller
body: <p>I am trying to post array of a simple object to my MVC core controller with the Frombody attribute, but for some reason it coming as null. If I post just a single object it is working fine here is my code: </p>
  
  <pre><code>$(document).ready(function() {
      var tk = new Array();
  
      $("#calendar").fullCalendar({
  
          header: {
              left: 'prevYear,prev,next,nextYear',
              center: 'title',
              right: 'month,agendaWeek,agendaDay',
          },
  
          defaultView: 'month',
          editable: true,
          alldayslot: false,
          selectable: true,
          slotminutes: 15,
          nextDayThreshold: "00:00:00",
          events: "/Home/FullCalendar",
          eventDrop: function(event, delta, revertFunc)
          {
              Update(event);
          },
      });
  
      function Update(event) {
          var datarow =
              {
                  "id": event.id, 
                  "start": event.start,
                  "end": event.end,
              }
          tk.push(datarow);
  
          debugger;
          confirm(("Save changes?"))
          console.log(JSON.stringify(datarow));
          $.ajax({
              type: "post",
              dataType: 'json',
              cache: false,
              contentType: "application/json; charset=utf-8",
              data: JSON.stringify(tk),
              url: '@Url.Action("JSON", "Home")',
              success: function (data) {
                  debugger;
              },
              error: function (xhr, ajaxOptions, thrownError) {
                  alert(xhr.status);
                  debugger;
              }
          });
      }
  });
  </code></pre>
  
  <p>My Controller class </p>
  
  <pre><code>[HttpPost]
  public IActionResult UpdateTask([FromBody] List&lt;Task_fullcal&gt; td)
  {
      // Do something
      // td is always null if passed as an array 
      //td working fine if passed as single value
  }
  </code></pre>