| title: 'Custom `_error` without /404' | |
| ## Why This Error Occurred | |
| You added a custom `/_error` page without adding a custom `/404` page. Adding a custom `/_error` typically opts your application out of having the automatic static optimization applied to the 404 page. | |
| ## Possible Ways to Fix It | |
| Add a `pages/404.js` with the 404 page you would like to show. | |
| ## Useful Links | |
| - [Automatic Static Optimization](/docs/pages/building-your-application/rendering/automatic-static-optimization) | |
| - [404 Page](/docs/pages/building-your-application/routing/custom-error#404-page) | |