title: datatables row toggle and fixedColumns
body: <p>I use datatable-row-toggle-option feature (grouping and collapsing rows)  </p>
  
  <p><a href="https://stackoverflow.com/questions/38371470/datatable-row-toggle-option">DataTable Row Toggle Option</a></p>
  
  <p>and need datatables.fixedColumns (first column is always show) </p>
  
  <p>but new created row with category make bug in fixedColumns plugin </p>
  
  <p>this throw error </p>
  
  <pre><code>Uncaught TypeError: Cannot read property 'anCells' of undefined
  at HTMLTableRowElement.&lt;anonymous&gt; (dataTables.fixedColumns.min.js:27)
  at Function.each (jquery.min.js:130)
  at init.each (jquery.min.js:49)
  at m._fnClone (dataTables.fixedColumns.min.js:27)
  at m._fnCloneLeft (dataTables.fixedColumns.min.js:23)
  at m._fnDraw (dataTables.fixedColumns.min.js:22)
  at HTMLTableElement.&lt;anonymous&gt; (dataTables.fixedColumns.min.js:13)
  at HTMLTableElement.dispatch (jquery.min.js:1199)
  at HTMLTableElement.y.handle (jquery.min.js:1153)
  at Object.trigger (jquery.min.js:1188)
  </code></pre>
  
  <p>this is my configuration :</p>
  
  <pre><code>var table = $('#example').DataTable( {
                          ajax: {                     
                          "drawCallback": function ( settings ) {
                              var api = this.api();
                              var rows = api.rows( {page:'current'} ).nodes();
                              var last=null;
  
                              api.column(1, {page:'current'} ).data().each( function ( group, i ) {
                                  if ( last !== group ) {
                                      $(rows).eq( i ).before(
                                          '&lt;tr class="group"&gt;&lt;td colspan="50"&gt;'+group+'&lt;/td&gt;&lt;/tr&gt;'
                                      );
  
                                      last = group;
                                  }
                              } );
                          },
                          "columnDefs": [
  
                              { "visible": false, "targets": 2 },
  
                              {
                                  "render": function ( data, type, row ) {
  
                                      return data+'&lt;a class="infoBtn"&gt;&lt;i class="fa fa-plus-circle"&gt;&lt;/i&gt;&lt;/a&gt; N/A';
                                  },
                                  targets: '_all',
                              }
  
                          ],
                          fixedColumns:   true,
  
                      } );
  </code></pre>