I met an issue, strange in my point of view.
I installed bootstrap via nuget package console.
After that, in BundleConfig.cs file, I added two items to bundles list:
bundles.Add(new ScriptBundle("~/bundles/bootstrap").Include(
"~/Scripts/bootstrap.min.js"));
bundles.Add(new StyleBundle("~/Content/bootstrap").Include(
"~/Content/bootstrap.min.css",
"~/Content/bootstrap-theme.min.css"));
Of course, these files exist locally.
The _Layout.cshtml file contains
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<title>@ViewBag.Title</title>
@Styles.Render("~/Content/css")
@Scripts.Render("~/bundles/modernizr")
@Styles.Render("~/Content/bootstrap")
</head>
<body>
@RenderBody()
@Scripts.Render("~/bundles/jquery")
@Scripts.Render("~/bundles/bootstrap")
@RenderSection("scripts", required: false)
</body>
</html>
But when I see a view (for example login page), I see that bundle doesn't append bootstrap part.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<title>Login</title>
<link href="/Content/Site.css" rel="stylesheet"/>
<script src="/Scripts/modernizr-2.6.2.js"></script>
<!-- I expect bootstrap here but it is not displayed -->
</head>
<body>
...
<script src="/Scripts/jquery-1.9.1.js"></script>
<!-- I expect bootstrap here but it is not displayed -->
</body>
</html>