Title: PHP Warning: Cannot modify header information
Last modified: November 10, 2022

---

# PHP Warning: Cannot modify header information

 *  [mesmer7](https://wordpress.org/support/users/mesmer7/)
 * (@mesmer7)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-19/)
 * I’m seeing hundreds of copies of this message in my wordpress error log
 *     ```
       [10-Nov-2022 04:10:51 UTC] PHP Warning:  Cannot modify header information - headers already sent in /home/mesmer17/public_html/wp-content/plugins/gridlist-view-for-woocommerce/includes/functions.php on line 26
       ```
   

Viewing 4 replies - 1 through 4 (of 4 total)

 *  [joeom](https://wordpress.org/support/users/joeom/)
 * (@joeom)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-19/#post-16186979)
 * Looks like the same error I’m getting (see my report 3 days ago), except for 
   me it takes down my whole website.
 *  Plugin Author [RazyRx](https://wordpress.org/support/users/razyrx/)
 * (@razyrx)
 * [3 years, 5 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-19/#post-16212232)
 * Hello,
 * Plugin uses cookie to store current list state and it must be set before header
   send.
    Plugin set it before WordPress sens any data, but maybe you have some 
   plugin that place some data before our plugin set cookie, that cause this issue,
   or some plugin has issue that cause this.
 * First of all please try to disable other plugins and change theme to WordPress
   default to check that it is not compatibility issue.
 * Regards,
    Oleg
 *  [LogicRays Technologies](https://wordpress.org/support/users/logicrays/)
 * (@logicrays)
 * [3 years ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-19/#post-16613845)
 * Hello,
 * I have try to disable other plugins and change theme to WordPress default still
   same PHP warning.
   Thanks
    -  This reply was modified 3 years ago by [LogicRays Technologies](https://wordpress.org/support/users/logicrays/).
 *  Thread Starter [mesmer7](https://wordpress.org/support/users/mesmer7/)
 * (@mesmer7)
 * [3 years ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-19/#post-16670378)
 * Still not resolved. I tried adding `SetEnv SERVER_NAME mydomain’ in my htaccess
   file. No effect.
 * Could this be caused by forcing HTTPS or by setting strict HTTPS headers?

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘PHP Warning: Cannot modify header information’ is closed to new replies.

 * ![](https://ps.w.org/gridlist-view-for-woocommerce/assets/icon-256x256.gif?rev
   =2772697)
 * [Grid/List View for WooCommerce](https://wordpress.org/plugins/gridlist-view-for-woocommerce/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/gridlist-view-for-woocommerce/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/gridlist-view-for-woocommerce/)
 * [Active Topics](https://wordpress.org/support/plugin/gridlist-view-for-woocommerce/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/gridlist-view-for-woocommerce/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/gridlist-view-for-woocommerce/reviews/)

 * 4 replies
 * 4 participants
 * Last reply from: [mesmer7](https://wordpress.org/support/users/mesmer7/)
 * Last activity: [3 years ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-19/#post-16670378)
 * Status: not resolved