# Invalid Layout or Page Export

#### Why This Error Occurred

Your [layout](https://beta.nextjs.org/docs/api-reference/file-conventions/layout) or [page](https://beta.nextjs.org/docs/api-reference/file-conventions/page) inside the app directory exports an invalid field. In these files, you're only allowed to export a default React component, or [Segment Configuration Options](https://beta.nextjs.org/docs/api-reference/segment-config) for layout and pages, such as `revalidate`, `generateStaticParams`, etc.

Other custom exports are not allowed to catch misspelt configuration options and prevent conflicts with future options.

#### Possible Ways to Fix It

You can create a new file and co-locate it with the page or layout. In the new file, you can export any custom fields and import it from anywhere.