title: Cannot read property 'prototype' of undefined, express
body: <p>Cannot read property 'prototype' of undefined, just seemed to randomly appear! I have no idea where it's coming from or why it is there. It's incredibly frustrating! All the browser is telling me is that it's coming from express, but obviously I've not modified the library so the error message is pretty much useless.</p>
  <pre><code>response.js:42 Uncaught TypeError: Cannot read property 'prototype' of undefined
  at Object.&lt;anonymous&gt; (response.js:42)
  at Object../node_modules/express/lib/response.js (response.js:1142)
  </code></pre>
  <p>So anyway I have built a MERN message board and integrated chat and webrtc videocalling with socket.io, and suddenly this error starts to appear. Oh, and I think it's important to note that I used  create-react-app for my client, so I'm not dealing with webpack, myself.</p>
  <p>I'm so clueless at the moment so please somebody help me out, here.</p>