Bootstrap4 dependency PopperJs throws error on Angular

Looking at the docs at https://getbootstrap.com/docs/4.2/getting-started/introduction/#js you can see that they import the following:

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

Note the naming: jquery.slim.min.js, umd/popper.min.js!

Therefore I used the following in my .angular-cli.json:

      "styles": [
        "../node_modules/bootstrap/dist/css/bootstrap.css"
      ],
      "scripts": [
        "../node_modules/jquery/dist/jquery.slim.min.js",
        "../node_modules/popper.js/dist/umd/popper.min.js",
        "../node_modules/bootstrap/dist/js/bootstrap.min.js"
      ],

After that it seems to work now.

I had the same problem. My solution was not to import the dist-folder (./node_modules/popper.js/dist/popper.js) but rather the umd-folder (./node_modules/popper.js/dist/umd/popper.js). Does not matter if you get the mini or normal version of the js-file.