session_start(): Cannot send session cache limiter - headers > already sent - codeigniter

Question

I knew that this question may mark as duplicate but I can't find my answer from any duplicated post so I decided to post it in my own.
I have a Pages with a session. after all task, there is a button that link into this controller called Profileresult.php but even I do not have a code yet its surprising me that I got this error.
here is the error.
A PHP Error was encountered
Severity: Warning
Message: session_start(): Cannot send session cache limiter - headers
already sent (output started at
/home3/oep2732/public_html/knowyourscore/application/controllers/Profileresult.php:1)
Filename: Session/Session.php
Line Number: 140
Backtrace:
File: /home3/oep2732/public_html/knowyourscore/index.php Line: 315
Function: require_once
I created a controller called Profileresult.php
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class Profileresult extends CI_Controller {
public function index()
{
}
}
?>

Answer 1

Check your controller file. Remove any empty space within that file. For example:
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class Profileresult extends CI_Controller {
public function index() {
//your codes here
}
}
?>
In your IDE, if you don't have any comment on top of <?php tag, make sure it is in line 1. No empty spaces. Same goes to at the end of ?> tag. If you have empty spaces after that. Those errors will occurs. I've encounter the same problem as yours. I tried to check my controller file as Aman Maurya said, and yes I have few lines of empty spaces. Removed that, that error not display anymore.