From English Error 404.
Error 404 – reasons
There are several reasons for this problem:
The link leads to a page that no longer exists
If the link leads to a page that no longer exists, you can restore it. If you no longer want to use this site, you can create another site instead. page with different content. The solution is also to create a page that will serve as a redirect to your new page.
Error setting URL
There may be an error setting the URLs. In this case, go to Settings ›Permalinks in the administration of your site. Check your settings and save any changes.