DataTables warning: table id={id} - Invalid JSON response.

I know " http://www.datatables.net/manual/tech-notes/1 "

But let know that same code and functionality is working properly on LOCALHOST without any error popup. but on my Online server i am getting above error message .. that to sometime i get and sometime it work perfectly .

Please let me know what will be issues

BELOW IS CODE :

    var oTableL1 = $('#table1').dataTable({
        "bProcessing": true, 
        "bServerSide": true,
        "sAjaxSource": "includes/db/list_db.php", 
        "fnServerParams": function ( aoData ) {
            aoData.push( { "name": "more_data", "value": "tablequeryone" } );
        }
    });

   //---------

      var oTableL2 = $('#table2').dataTable({
        "bProcessing": true, 
        "bServerSide": true,
        "sAjaxSource": "includes/db/list_db.php", 
        "fnServerParams": function ( aoData ) {
            aoData.push( { "name": "more_data", "value": "tablequerytwo" } );
        }
    });


   
   //---------

      var oTableL3 = $('#table3').dataTable({
        "bProcessing": true, 
        "bServerSide": true,
        "sAjaxSource": "includes/db/list_db.php", 
        "fnServerParams": function ( aoData ) {
            aoData.push( { "name": "more_data", "value": "tablequerythree } );
        }
    });