Not found (page title)
generateMetadata sets the document title to Not found (no period) when the path is not a known file id and not a published CMS page. The body is usually a generic or designed 404.
Why this happens
Typo’d URL, deleted CMS page, or junk slug under the marketing download router. Distinct from API Not found. (with period) and from File not found (page title).
Diagnose and fix
1. Check the URL — open a valid file link or published page.
2. Publish/restore the CMS page if that slug should exist.
3. No Users & limits setting fixes a missing route.
4. For API JSON 404s, see Not found.