A “404 Page Not Found” error indicates that the requested web page could not be found on the server. Here are steps to troubleshoot and address the issue:

1. Check the URL:
   • Ensure that the URL you are trying to access is correct. Verify that there are no typos, extra spaces, or incorrect characters in the URL.
2. Check File and Directory Names:
   • Confirm that the file or directory you are trying to access exists on the server and that the names are spelled correctly, including letter case (URLs are case-sensitive).
3. Review Server Logs:
   • Check the server logs for more details about the 404 error. Server logs can provide information about the requested URL, the referring page, and any server-side issues.
4. Check for URL Rewriting Issues:
   • If your website uses URL rewriting (e.g., mod_rewrite in Apache), check the rewrite rules in your .htaccess file or server configuration. Incorrect rules can lead to 404 errors.
5. Examine .htaccess File:
   • Review your website’s .htaccess file for any misconfigurations or rules that may be causing the 404 error. Ensure that the file is in the correct location and is properly configured.
6. File Permissions:
   • Check the file and directory permissions on the server. Ensure that the web server has the necessary permissions to access and serve the requested files.
7. Check for Redirects:
   • If there are redirects configured for the URL, ensure that they are set up correctly. Incorrect redirects can result in 404 errors.
8. Check DNS Configuration:
   • Verify that the domain’s DNS configuration is correct. DNS issues can lead to the inability to resolve the correct server IP address.
9. Review CMS Configuration:
   • If your website is built on a content management system (CMS) like WordPress, Joomla, or Drupal, check the CMS settings for the page in question. Ensure that the page exists and is published.
10. Restore from Backup:
    • If the 404 error occurred after recent changes, consider restoring the website from a backup to a point where the page was accessible. This can help eliminate issues introduced during recent updates.
11. Check for .html/.php Extensions:
    • If the URL includes a file extension (e.g., .html, .php), ensure that the file exists and the extension is correct. Additionally, check if your server is configured to hide file extensions.
12. Clear Browser Cache:
    • Clear your browser’s cache and try accessing the page again. Cached pages may lead to persistent 404 errors.
13. Use Webmaster Tools:
    • If your website is registered with Google Search Console or other webmaster tools, check for crawl errors and 404 reports. These tools can provide insights into URLs that are not found during crawling.

If the issue persists after performing these checks, you may need to consult with your hosting provider’s support or website developer for further assistance. They can analyze server configurations, logs, and other specifics to identify the root cause of the 404 error.