Default error page not rendering (using Next.js)

Hi all,

I have an Auth0 application running in Next.js. I have an Auth0 rule set up that returns callback(new UnauthorizedError('{error message…}')) if a certain condition is met based on the user’s entered signup details.

When that rule is enforced on a user signing up, it redirects to this URL:

{baseURL}/api/auth/callback?error=unauthorized&error_description={error message…}&state={long hash string…}

What happens: The shows a 400 server response error page with no rendering.

What I expect to happen: A default Auth0 error page, per

Using @auth0/nextjs-auth0@2.5.0 and next@13.2.3.

The tenant error page setting is set to display “Generic” page, not “Custom”

Why am I not seeing the generic error page when my Auth0 Rule is enforced?