Script timed out before returning headers: admin-ajax.php

Good day! I have tried doing the solutions here: https://stackoverflow.com/questions/11225932/script-timed-out-before-returning-headers-php-fastcgi

But error still persist so I tried setting max_execution_timeout: 600

After restarting my apache, I am now receiving this error: Script timed out before returning headers: post.php

Then after a while continued with receiving this error: Script timed out before returning headers: admin-ajax.php

What should I increase or change?

Hi, first of all you have to check the website log in /usr/local/apache/domlogs/ There are too many reasons for the error.