If you get 404 Not Found error then make sure that your .htaccess file in your WordPress’s main directory has following rules :
RewriteBase / RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.php [L]
If you don’t have a .htaccess file, then create one that contains all the above rules, and it will allow you to use SEF on the webserver.
For such types of technical errors contact our support team for help.
Also Read :
1) How to create custom pages for 404 not found error in cPanel?