I managed to get around this problem by downloading the latest (1.12.3 at the time of writing) popper.js nuget package before updating to bootstrap 4.0.
Then in the bundles.config I added the popper js like this
bundles.Add(new ScriptBundle("~/bundles/popper").Include(
"~/Scripts/umd/popper.js"));
The umd version is the only one that worked for me the others gave an console error of
Unrecognised Token Export
Just make sure to include the popper js file before the bootstrap one.
@Scripts.Render("~/bundles/popper")
@Scripts.Render("~/bundles/bootstrap")
I also noticed that this then broke the majority of the auto produced template as it's based on previous versions of bootstrap. The navbar almost completely vanishes. I managed to fix mine by replacing it with the following, but this doesn't include any items in the mobile menu.
<div class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="#">My Blog</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse">
<ul class="navbar-nav">
<li class="nav-item">@Html.ActionLink("Home", "Index", "Home", new { @class = "nav-link" })</li>
<li class="nav-item">@Html.ActionLink("About", "About", "Home", new { @class = "nav-link" })</li>
<li class="nav-item">@Html.ActionLink("Contact", "Contact", "Home", new { @class = "nav-link" })</li>
</ul>
</div>
</div>
I know this question has a few good answers but this was the full solution that worked for me so I thought I'd share it in the hope that it spares someone a bit of time in the future.
