Cannot read property 'mData' of undefined - Datatables

Question

I have a table that is getting data from nodejs in Pug. I'm trying to make it a DataTable, so I've followed the steps needed in order to do that. However, I am getting an error 'Cannot read property 'mData' of undefined'. I have included both css and js file needed for DataTables. I found few posts related to the same error, but most of them seems to be due to missing thead/tbody which is not the case in below code.

    script(type='text/javascript', src='/DataTables/datatables.js')
    link(rel='stylesheet', href='/DataTables/datatables.css', type='text/css')
    script.
      $(document).ready(function() {
        $('#dtable').DataTable();
      });

table(id='dtable')
        thead
          tr
            th= tbl_header1
            th= tbl_header2
            th= tbl_header3
            th= tbl_header4
            th= tbl_header5
            th= tbl_header6
            th= tbl_header7
            th= tbl_header8
            th= tbl_header9
            th= tbl_header10
            th= tbl_header11
            th= tbl_header12
            th= tbl_header13
        tbody
          each item in items
            if (typeof(item.schema_name) !== 'undefined')
              tr
                td= item.entity_id
                td= item.database_name
                td= item.schema_name
                td= item.entity_name
                td= item.entity_type
                td= item.db_user
                td= item.entity_owner
                td= item.external_table_location
                td= item.entity_description
                td= item.status
                td= item.latest_refresh_column
                td
                  button(class="use-address" id="button" type="button") Edit