Requested unknown parameter '7' from the data source for row 0

BharathPalaksha

Requested unknown parameter '7' from the data source for row 0
This error is pointing to the 7th column in my row and this is my code in 7th column

{
                            "sWidth" : "200px",
                            "sTitle" : dnsServersTitle,
                            "fnRender" : function (oObj)
                            {
                               var dns = [];
                               for(var key in oObj.aData.dnsNames)
                               {
                                   dns.push(oObj.aData.dnsNames[key]);
                               }
                               return dns.join('
');
                            }
  }

can you please tell me what wrong am doing here ?
I have render function instead of mData or mDataProp, read somewhere that if i use mDataProp, this error doesn't occur