NUXT_E4016
A nested page cannot be displayed because its parent page does not render <NuxtPage />.
E4016
The current route matches a nested page, but the parent page component does not render <NuxtPage />. Vue Router can only display a child page inside its parent's <NuxtPage /> outlet, so the child page is never shown.
This happens with a directory structure like the following, when parent.vue does not contain <NuxtPage />:
Directory Structure
-| pages/
---| parent/
------| child.vue
---| parent.vue
Resolution
Add <NuxtPage /> to the parent page component so the child route can render inside it. If you did not intend to create a nested route, restructure your pages/ directory so the page no longer has child routes.