JQuery Uncaught TypeError

Question

我有一个问题，我有时会收到以下错误。我导入的jQuery文件如下。奇怪的是它偶尔只显示错误。我正在为bPopup使用jquery.bpopup.min.js。有时我会在弹出这个弹出窗口时收到此错误。

我在网站上使用的JQuery文件并订购

<link href="/stylesheets/styles.css" rel="stylesheet" type="text/css" />
<!--for autocompleter-->
<link href="/javascript/autocomplete/jquery.autocomplete.css" rel="stylesheet" type="text/css" />

<script type="text/javascript" src="/javascript/jquery.js"></script>
<script type="text/javascript" src="/javascript/jquery.validate.js"></script>
<script type="text/javascript" src="/javascript/autocomplete/jquery.autocomplete.min.js"></script>
<script type="text/javascript" src="/javascript/jquery.maskedinput.js"></script>
<script type="text/javascript" src="/javascript/design.js"></script>

<script type="text/javascript" src="/javascript/forms.js"></script>
<script type="text/javascript" src="/javascript/validations.js"></script>
<!-- Date-Picker Style and Script START -->
<link type="text/css" href="/css/cupertino/jquery-ui-1.8.5.custom.css" rel="stylesheet" />  
<script type="text/javascript" src="/javascript/jquery-ui-1.8.5.custom.min.js"></script>
<link rel="stylesheet" href="/stylesheets/mapStyle.css" type="text/css" />

<script type="text/javascript" src="/javascript/jquery.bpopup.min.js"></script>

任何人都可以告诉我出现此错误的原因吗？有没有发生冲突？你能帮我找一下冲突吗？