Title: Cannot modify header information – Warning !
Last modified: August 19, 2016

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# Cannot modify header information – Warning !

 *  [dipenrique](https://wordpress.org/support/users/dipenrique/)
 * (@dipenrique)
 * [15 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-warning/)
 * After updating to latest wordpress,I am receiving following warning.
    I am not
   sure if its a plugin thats causing the problem,or some wordpress core file has
   changed.
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/xyz/public_html/wp-includes/post.php:5254) in /home/xyz/public_html/
   wp-includes/pluggable.php on line 897
 * Please help me fix it.

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Moderator [Ipstenu (Mika Epstein)](https://wordpress.org/support/users/ipstenu/)
 * (@ipstenu)
 * 🏳️‍🌈 Advisor and Activist
 * [15 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-warning/#post-2008919)
 * [http://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F](http://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F)
 *  Thread Starter [dipenrique](https://wordpress.org/support/users/dipenrique/)
 * (@dipenrique)
 * [15 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-warning/#post-2009090)
 * Yes it did help.
 * At the end of
    /home/xyz/public_html/wp-includes/post.php:5254 there was a line
   as follows- “//Do Not Delete This code line PCJ”
 * I removed this line in the php file that was causing the problem.But I am still
   facing the problem.The line again appears at the end of the php file and i dont
   know why.
 * I changed the post.php file’s permission and set it to non writable,but even 
   then after running site once,somehow this line gets added at the end of post.
   php file.
 * Please help….
 *  Thread Starter [dipenrique](https://wordpress.org/support/users/dipenrique/)
 * (@dipenrique)
 * [15 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-warning/#post-2009091)
 * And thanks for replying earlier 🙂

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘Cannot modify header information – Warning !’ is closed to new replies.

## Tags

 * [header information](https://wordpress.org/support/topic-tag/header-information/)
 * [header warning](https://wordpress.org/support/topic-tag/header-warning/)
 * [modify header information](https://wordpress.org/support/topic-tag/modify-header-information/)
 * [warning](https://wordpress.org/support/topic-tag/warning/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 3 replies
 * 2 participants
 * Last reply from: [dipenrique](https://wordpress.org/support/users/dipenrique/)
 * Last activity: [15 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-warning/#post-2009091)
 * Status: not resolved

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