title: React @material-ui/core - v4.11.0 - "the createMuiTheme function was renamed to createTheme" console error
body: <p>My react project only logging this error(console error) when the service on production level. I don't see the following error on my local, but only on production mode.</p>
  <pre><code>Material-UI: the createMuiTheme function was renamed to createTheme. You should use `import { createTheme } from '@material-ui/core/styles'`
  </code></pre>
  <p>I found a few articles saying this only happens when anything above <code>v5 of @material-ui/core</code> has been used. However, I'm using <code>v4.11.0 of @material-ui/core</code> which only supports <code>createMuiTheme</code>. Since the version is below <code>v5</code>, I reckon the error should not be shown at any point during runtime.</p>
  <p>For those who have any clue regarding this issue, please share. Thank you.</p>