除了不一致的数字之外，数据表脚本列部分中缺少的项目也会导致这种情况。修正这修正了我的数据表搜索栏。

我说的是这部分;

"columns": [
  null,
  .
  .
  .
  null
           ],

我在这个错误中苦苦挣扎，直到有人指出，这个部分的“null”比我的总人头数少一个。

对于那些使用GridView在webform中工作的人:

摩西的回答完全正确。但由于我们正在生成表格，默认情况下不会生成thead标记。所以要解决这个问题，添加[YourGridViewID]. headerrow。TableSection = TableRowSection。TableHeader到后端，在DataBind()方法调用的下面(如果您正在使用它)。这个配置将GridView中Field的HeaderText值作为它在头部内生成的th标签的值。

我遇到了同样的问题，但我是动态生成表。在我的例子中，我的表缺少<thead>和<tbody>标签。

下面是我的代码片段，如果它对某人有帮助的话

   //table string
   var strDiv = '<table id="tbl" class="striped center responsive-table">';

   //add headers
   var strTable = ' <thead><tr id="tableHeader"><th>Customer Name</th><th>Customer Designation</th><th>Customer Email</th><th>Customer Organization</th><th>Customer Department</th><th>Customer ContactNo</th><th>Customer Mobile</th><th>Cluster Name</th><th>Product Name</th><th> Installed Version</th><th>Requirements</th><th>Challenges</th><th>Future Expansion</th><th>Comments</th></tr> </thead> <tbody>';


  //add data
  $.each(data, function (key, GetCustomerFeedbackBE) {
                            strTable = strTable + '<tr><td>' + GetCustomerFeedbackBE.StrCustName + '</td><td>' + GetCustomerFeedbackBE.StrCustDesignation + '</td><td>' + GetCustomerFeedbackBE.StrCustEmail + '</td><td>' + GetCustomerFeedbackBE.StrCustOrganization + '</td><td>' + GetCustomerFeedbackBE.StrCustDepartment + '</td><td>' + GetCustomerFeedbackBE.StrCustContactNo + '</td><td>' + GetCustomerFeedbackBE.StrCustMobile + '</td><td>' + GetCustomerFeedbackBE.StrClusterName + '</td><td>' + GetCustomerFeedbackBE.StrProductName + '</td><td>' + GetCustomerFeedbackBE.StrInstalledVersion + '</td><td>' + GetCustomerFeedbackBE.StrRequirements + '</td><td>' + GetCustomerFeedbackBE.StrChallenges + '</td><td>' + GetCustomerFeedbackBE.StrFutureExpansion + '</td><td>' + GetCustomerFeedbackBE.StrComments + '</td></tr>';
                        });

//add end of tbody
 strTable = strTable + '</tbody></table>';

//insert table into a div                 
   $('#divCFB_D').html(strDiv);
   $('#tbl').html(strTable);


    //finally add export buttons 
   $('#tbl').DataTable({
                            dom: 'Bfrtip',
                            buttons: [
                                'copy', 'csv', 'excel', 'pdf', 'print'
                            ]
                        });

无法读取未定义的属性'fnSetData'的常见原因是列数不匹配，就像下面的错误代码:

<thead>                 <!-- thead required -->
    <tr>                <!-- tr required -->
        <th>Rep</th>    <!-- td instead of th will also work -->
        <th>Titel</th>
                        <!-- th missing here -->
    </tr>
</thead>
<tbody>
    <tr>
        <td>Rep</td>
        <td>Titel</td>
        <td>Missing corresponding th</td>
    </tr>
</tbody>

下面的代码中，每<td>(列数必须匹配)包含一个<th>:

<thead>
    <tr>
        <th>Rep</th>       <!-- 1st column -->
        <th>Titel</th>     <!-- 2nd column -->
        <th>Added th</th>  <!-- 3rd column; th added here -->
    </tr>
</thead>
<tbody>
    <tr>
        <td>Rep</td>             <!-- 1st column -->
        <td>Titel</td>           <!-- 2nd column -->
        <td>th now present</td>  <!-- 3rd column -->
    </tr>
</tbody>

当使用带有colspan但没有第二行的格式良好的标题时，也会出现这种错误。

对于一个有7列的表，下面的不工作，我们看到“不能读取属性'mData' of undefined”在javascript控制台中:

<thead>
    <tr>
        <th>Rep</th>
        <th>Titel</th>
        <th colspan="5">Download</th>
    </tr>
</thead>

虽然这是有效的:

<thead>
    <tr>
        <th rowspan="2">Rep</th>
        <th rowspan="2">Titel</th>
        <th colspan="5">Download</th>
    </tr>
    <tr>
        <th>pdf</th>
        <th>nwc</th>
        <th>nwctxt</th>
        <th>mid</th>
        <th>xml</th>
    </tr>
</thead>

供参考，数据表需要一个格式良好的表。它必须包含<thead>和<tbody>标签，否则将抛出此错误。还要检查确保包括标题行在内的所有行具有相同的列数。

以下将抛出错误(没有<thead>和<tbody>标签)

<table id="sample-table">
    <tr>
        <th>title-1</th>
        <th>title-2</th>
    </tr>
    <tr>
        <td>data-1</td>
        <td>data-2</td>
    </tr>
</table>

下面也会抛出一个错误(列数不等)

<table id="sample-table">
    <thead>
        <tr>
            <th>title-1</th>
            <th>title-2</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>data-1</td>
            <td>data-2</td>
            <td>data-3</td>
        </tr>
    </tbody>
</table>

更多信息请点击这里

我在通过脚手架生成器创建的Rails视图中使用DOM数据时遇到了同样的问题。默认情况下，视图为最后三列(包含显示、隐藏和销毁记录的链接)省略<th>元素。我发现，如果我在<thead>内的<th>元素中为这些列添加标题，它就解决了这个问题。

I can't say if this is the same problem you're having since I can't see your html. If it is not the same problem, you can use the chrome debugger to figure out which column it is erroring out on by clicking on the error in the console (which will take you to the code it is failing on), then adding a conditional breakpoint (at col==undefined). When it stops you can check the variable i to see which column it is currently on which can help you figure out what is different about that column from the others. Hope that helps!