MVC bootstrap navbar not working after running NuGet updates

Question

An MVC app broke after we updated all the NuGet packages. After trying everything I created a new MVC app, updated the NuGet packages and the basic navbar...

<div class="navbar navbar-inverse navbar-fixed-top">
    <div class="container">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="/">Application name</a>
        </div>
        <div class="navbar-collapse collapse">
            <ul class="nav navbar-nav">
                <li><a href="/">Home</a></li>
                <li><a href="/Home/About">About</a></li>
                <li><a href="/Home/Contact">Contact</a></li>
            </ul>

<ul class="nav navbar-nav navbar-right">
    <li><a href="/Account/Register" id="registerLink">Register</a></li>
    <li><a href="/Account/Login" id="loginLink">Log in</a></li>
</ul>


        </div>
    </div>
</div>

... looks like this ...

...and clicking the icon...

Any ideas what could be causing this?

Have tried manually adding Bootstrap.css and Bootstrap.js to _Layout.vbhtml, but no difference

Thank you

Answer 1

Finally, I managed my HTML and yours. There're a lot of changes in Bootstrap 4 in compare to version 3. Regarding your markup, you have to change:

1. "Navbar-inverse" to "Navbar-dark" and use color "bg-dark".
2. Add few attributes to button, as "aria-controls", "aria-expanded", "aria-label" and "data-target" for link to another element.
3. Property "id" to collapsable element.
4. For list elements (tag LI) should be added class="nav-item"
5. For links unside list elements add class="nav-link".
6. I suggest to add "mr-auto" to list definiton.

All changes below. Tested here.

<nav class="navbar navbar-expand-sm navbar-dark fixed-top bg-dark">
  <div class="container">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    </button>
    <a class="navbar-brand" href="/">Application name</a>
    <div class="navbar-collapse collapse" id="navbarSupportedContent">
      <ul class="nav navbar-nav mr-auto">
        <li class="nav-item"><a href="/" class="nav-link">Home</a></li>
        <li class="nav-item"><a href="/Home/About" class="nav-link">About</a></li>
        <li class="nav-item"><a href="/Home/Contact" class="nav-link">Contact</a></li>
      </ul>

      <ul class="nav navbar-nav navbar-right mr-auto">
        <li class="nav-item"><a href="/Account/Register" id="registerLink" class="nav-link">Register</a></li>
        <li class="nav-item"><a href="/Account/Login" id="loginLink" class="nav-link">Log in</a></li>
      </ul>

    </div>
  </div>
</nav>