title: Angular TypeError: Cannot read property 'selectors' of null After Upgrading to Angular v9
body: <p>I recently upgraded my Angular app from v7 to v8, and then v8 to v9. Locally it works perfectly if I run <code>ng serve</code>. But when I run a production build, <code>ng build --prod</code>, and deploy the app I get an error in the console of the application:</p>
  <p><a href="https://i.stack.imgur.com/Gfu1J.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Gfu1J.png" alt="TypeError: Cannot read property 'selectors' of null" /></a></p>
  <p>I can't find anything helpful to solve the issue. I did find a couple other people who had this issue, but no solutions. Any ideas would be greatly appreciated.</p>