title: Vue: Uncaught (in promise) TypeError: Cannot read property '_c' of undefined
body: <p>I need to upgrade project from vue 2 to vue3
  I am using coreui template. And in that I have upgrade vue, vuex, vue-router.
  But when I serve the project it shows the following error in console.</p>
  <blockquote>
  <p>Uncaught (in promise) TypeError: Cannot read property '_c' of undefined</p>
  </blockquote>
  <p><a href="https://i.stack.imgur.com/ac3Ga.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ac3Ga.png" alt="" /></a></p>
  <p>There is no error in terminal. I have updated all router, vuex, vue with vue3 syntax.</p>
  <p>Thanks for any help</p>