If there was a situation where we face a 404 error in the WordPress 
site,
then we have to follow some steps
*)By clearing the browsers cache we can avoid the error 
*)when ever we do some changes in the page and didn't do the 
  restoring then also we face the error
*)Even some times the plugins that we use in the WordPress 
  may also be the reason for that

 These are some steps to avoid the 404 error on the WordPress page