Requested unknown parameter '0' from the data source for row 0

The minimal code for the ajax loading of rows is as below.

$table
    .dataTable({
      "bServerSide": true,
      "sAjaxSource": "/deals/deal_data",
       fnRowCallback: function(tr, data){
         var $html = $(data.html_row);
         var $tr = $(tr);
         $tr.html($html.html());
      }
    });

Data returned from server in the following format.

{
aaData: [
   {
     html_row: '<tr><td attr1=val1 attr2=val2>hello</td><td newattr=valnew newattr1=val1>cells</td></tr>'
   }
 ]
}

Now I understand why data-table is giving this alert error. As you see I am custom populating the cells.
How can I stop datatable from raising the alert 'Requested unknown parameter '0' from the data source for row 0'.?