Encountering a WordPress 404 error, where pages or posts cannot be found, can be perplexing. This issue often stems from various sources, including permalink problems, corrupted .htaccess files, or conflicting plugins. Here’s a detailed guide to help you diagnose and fix the WordPress 404 error:

1. Check Permalink Settings to fix 404 Error:

  • Go to the WordPress dashboard.
  • Navigate to “Settings” > “Permalinks.”
  • Choose a different permalink structure and save changes.
  • Revert to your preferred structure and save again.
  • This can refresh your permalink settings and resolve issues.

2. Regenerate .htaccess File:

  • Access your site’s root directory via FTP or file manager.
  • Locate the .htaccess file and rename it (e.g., to .htaccess_backup).
  • Go to “Settings” > “Permalinks” in the WordPress dashboard and click “Save Changes.”
  • WordPress will regenerate a new .htaccess file.

3. Review .htaccess File Manually:

  • Open the .htaccess file in a text editor.
  • Ensure it contains the correct directives. A typical WordPress .htaccess file looks like this:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]


# BEGIN WordPress
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
  • Save the file.

4. Flush Rewrite Rules:

  • In some cases, rewriting rules need to be flushed.
  • Add the following code to your theme’s functions.php file: 
flush_rewrite_rules(true);
  • Save the file, and then remove the code after refreshing your site.

5. Check for Plugin Conflicts:

  • Deactivate all plugins.
  • Check if the 404 error persists.
  • If resolved, reactivate plugins one by one to identify the conflicting one.