Error "Message: Cannot modify header information - headers already sent" pada PHP 7.4.3

[zickkeen]

Versi php yang digunakan:

PHP 7.4.3 (cli) (built: Nov 25 2021 23:16:22) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with Zend OPcache v7.4.3, Copyright (c), by Zend Technologies
   with Xdebug v2.9.2, Copyright (c) 2002-2020, by Derick Rethans

Error yang muncul:

A PHP Error was encountered
Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /var/www/arsip/arteri/application/third_party/htmlpurifier-4.10.0-standalone/HTMLPurifier.standalone.php:14584)

Filename: controllers/Home.php

Line Number: 402

Backtrace:

File: /var/www/arsip/arteri/application/controllers/Home.php
Line: 402
Function: header

File: /var/www/arsip/arteri/index.php
Line: 328
Function: require_once