Warning message

This is usually a whitespace problem. Check your wp-config file for whitespace before the first <? and after the last ?>

A simple search of the forums would have pointed you to the solution that shadow mentions.

https://codex.www.ads-software.com/Installing_WordPress#Common_Installation_Problems

https://codex.www.ads-software.com/Answers-Trouble_Shooting#Headers_already_sent

So, wasn’t my description good enough or something?

It looks to me like all of the following suggestions reiterate my initial answer.

Oh, it was. Sorry, I just tend to run on autopilot when I see “headers already send” or “enable sending refers”. Especially since most people never search before posting.

Shadow,
Your explanation was fine, but it never hurts to point people to specific resources. It’s part of the process of “training” users to know where else they can look for answers.

Hi all, thanks for your answer. I find the problem finally. It is just some strange spaces in the script. Sorry for inconvenience.