A 404 means the requested page or file doesn't exist at that address.

1. Check the URL for typos.
2. Confirm the file exists in the right folder via File Manager (article 105).
3. WordPress permalinks: if internal links 404 after a change or migration, go to Settings > Permalinks and click Save to rebuild the rules.
4. Check .htaccess is present in public_html (WordPress needs it for pretty permalinks).
5. Set a custom 404 page under Advanced > Error Pages for a friendlier message.

Tip: A site-wide 404 on every page is usually a permalink/.htaccess issue — re-saving permalinks fixes it most of the time.