dataTables.js requires you to have "good" tables. If your table has an uneven number of columns per row, and you're getting the dreaded " Cannot read property 'mData' of undefined " this will fix it.

dataTables_patch.js

// dataTables.js is great!  But it requires you to have "good" tables in
// the first place. If your table has an uneven number of columns per
// row, and you're getting the dreaded "Cannot read property
// 'mData' of undefined" this'll fix it.  If you're missing a thead or 
// tbody you'll get that error too - this won't fix that!

$(document).ready(function() {
  // We need to make sure every row in our table has the same number of columns.
  // Otherwise dataTable doesn't work.
  $('table').each(function(i, elm) {
    elm = $(elm);

    // Get the longest row length.
    var maxsize = 0;
    var trs = elm.find('tr');
    trs.each(function(i, tr) {
      if($(tr).find('td,th').length > maxsize) {
        maxsize = $(tr).find('td,th').length;
      }
    });

    // Repeat the loop, this time padding out our rows
    trs.each(function(i, tr) {
      var tr = $(tr);
      var missing = maxsize - tr.find('td,th').length;
      if(missing > 0) {
        var extra_elms = '<td></td>';
        if(tr.parent().prop('tagName').toLowerCase() === 'thead') {
          extra_elms = '<th></th>';
        }

        for(i=0; i<missing; i++) {
          tr.append(extra_elms);
        }
      }
    });
  });

  //
  // Put your actual call to dataTable here!!!!
  // $('table').dataTable({
  //      'scrollY': '400px',
  //      'scrollX': true,
  //      'scrollCollapse': true,
  //      'paging': false,
  //      'ordering': false,
  //      'info': false
  //  });
});