Uncaught Type Error: Undefined is not a function JavaScript

Question

In the script section, i get the Uncaught Type Error: Undefined is not a function JavaScript error. What might be wrong? I checked to see if the .js files have been called, and everything is in order.

@model Crux.Models.Question
@{
  ViewBag.Title = "Create";
  Layout = "~/Views/Shared/_Layout.cshtml";
}
<link href="~/Content/jquery.tagit.css" rel="stylesheet" />
<script src="~/Scripts/jquery-2.1.1.min.js"></script>
<script src="~/Scripts/jquery-ui.js"></script>
<script src="~/Scripts/tag-it.js"></script>
<link href="~/Content/jquery-ui.min.css" rel="stylesheet" />

<h2>Create</h2>
@using (Html.BeginForm())
{
  @Html.AntiForgeryToken()
  <div class="form-horizontal">
    <h4>Question</h4>
    <hr />
    @Html.ValidationSummary(true)
    <div class="form-group">
      @Html.LabelFor(model => model.question, new { @class = "control-label col-md-2" })
      <div class="col-md-10">
        @Html.EditorFor(model => model.question)
        @Html.ValidationMessageFor(model => model.question)
      </div>
    </div>
    <div class="form-group">
      <label for="hashtags" class="control-label col-md-2">Tags</label>
      <div class="col-md-10">
        <input id="hashtags" name="hashtags" class="form-control">
      </div>
    </div>
    <div class="form-group">
      <div class="col-md-offset-2 col-md-10">
        <input type="submit" value="Create" class="btn btn-default" />
      </div>
    </div>
  </div>
}
<div>
  @Html.ActionLink("Back to List", "Index")
</div>

<script type="text/javascript">
  $(document).ready(function () {
    $("#hashtags").tagit({
      allowSpaces: false,
      singleField: true,
      singleFieldNode: $('#hashtags'),
      availableTags: ["c++", "java", "php", "javascript", "ruby", "python", "c"]
    });
  }); 
</script>

It gives the error on line: $("#hashtags").tagit({

Answer 1

I was clashing jQuery by loading it three different times. from bundles and the page itself. removed all the links, and finally worked.