jquery ajax datatable error - php

Question

I am getting this error:
DataTables warning: table id=discount_html - Requested unknown parameter '0' for row 0. For more information about this error, please see http://datatables.net/tn/4
My code is:
$('#abcd').DataTable({
"processing":true,
"serverSide":true,
"destroy" : true,
"order":[],
"pageLength": 50,
"columnDefs": [
{ "orderable": false, "targets": 0 }
],
"ajax":{
url: 'abc.php',
type:"POST",
"data": function(d){
var frm_data = $('form').serializeArray();
$.each(frm_data, function(key, val) {
d[val.name] = val.value;
});
},
dataSrc: function (json) {
var return_data = new Array();
if(json.data.length > 0){
var obj = json.data;
console.log(obj);
return obj;
}
return return_data;
},
"columns" : [
{'data':'input'},
{'data': 'date'},
{'data': 'id'},
{'data': 'pname'},
{'data': 'cname'},
{'data': 'clname'},
{'data': 'dname'},
{'data': 'act'}
]
},
});
This is my AJAX response:
"draw":1,
"recordsTotal":1073,
"recordsFiltered":1073,
"data":[
{
"input":"<input data-id = "0" type="checkbox" name="report[]" class="allCheck" value="1234">",
"date":"2018-01-29",
"id":"1244",
"pname":"XYZ",
"cname":"adasdasd",
"clname":"NA",
"dname":"asdasdasdas",
"act":"hgh"
},
{
"input":"<input data-id = "1" type="checkbox" name="report[]" class="allCheck" value="23232">",
"date":"2018-01-29",
"id":"23232",
"pname":"aaaaa",
"cname":"asdasdsadasdsa",
"clname":"ewqweqewq",
"dname":"aaaaaaaa",
"act":"hgh"
},
and below is the HTML:
<tr>
<th><input type="checkbox" name="" id="checkAll"></th>
<th class="recept_td01">Date </th>
<th class="recept_td03">Code</th>
<th class="recept_td04">Name</th>
<th class="recept_td05">Ce</th>
<th class="recept_td05">Cli</th>
<th class="recept_td06">Doc</th>
<th class="recept_td07" id="action">Action</th>
</tr>
What am I doing wrong, that I am getting that error, tried everything but nothing seems to be working.