By default ImpressPages CMS shows error 404 page with possible reason of it. To configure ImpressPages CMS error 404 behavior, please open administration panel, and go to Developer -> Modues Config -> Configuration -> Error 404.
Here you can:
- change appearing texts;
- setup error 404 reporting via e-mail;
- setup redirect to main page.
If you found this page while looking why all your links result in error 404, please visit "links don't work" page.