title: Bootstrap 4: Uncaught ReferenceError: Popper is not defined
body: <p>I've installed Bootstrap 4 using Node and Gulp and when running the application I get the following error </p>
  
  <blockquote>
    <p>Uncaught ReferenceError: Popper is not defined</p>
  </blockquote>
  
  <p>I've only been using the Bootstrap grid system so far and I haven't used anything that would require the Bootstrap JS. Looks to me like Bootstrap is missing something or I haven't installed it correctly (to be honest it's probably me) - has anyone else come across the same issue or know a fix at all? </p>