Title: PHP Warning: Cannot modify header information
Last modified: October 7, 2023

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# PHP Warning: Cannot modify header information

 *  Resolved [dimal](https://wordpress.org/support/users/dimalifragis/)
 * (@dimalifragis)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/)
 * After this today’s update, tones of those:
 * PHP Warning: Cannot modify header information – headers already sent in /home/
   wp-content/plugins/very-simple-contact-form/vscf.php on line 133
 * thanks

Viewing 11 replies - 1 through 11 (of 11 total)

 *  Plugin Author [Guido](https://wordpress.org/support/users/guido07111975/)
 * (@guido07111975)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17107459)
 * Hi,
 * Thanks for reporting, have to look into this. This might be a conflict with another
   plugin, because I don’t have this issue.
 * Guido
 *  Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/)
 * (@dimalifragis)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17107495)
 * Downgraded to previous version and all ok now.
 *  Plugin Author [Guido](https://wordpress.org/support/users/guido07111975/)
 * (@guido07111975)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17107588)
 * Was whole site down or only a warning?
 * Current version uses a cookie, somehow it causes the headers already sent issue
   in some cases.
 * Guido
 *  Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/)
 * (@dimalifragis)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17107636)
 * Just the warnings on debug log.
 *  Plugin Author [Guido](https://wordpress.org/support/users/guido07111975/)
 * (@guido07111975)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17107703)
 * Hi,
 * I have updated multiple sites but no issue with this. So I think it’s a conflict
   with another plugin.
 * Are you able/willing to do a test after you’ve updated plugin? 
   If you are, open
   the plugin editor, go to file vscf and look for:
 *     ```wp-block-code
       add_action( 'init', 'vscf_cookie', 10 );
       ```
   
 * Change into:
 *     ```wp-block-code
       add_action( 'send_headers', 'vscf_cookie' );
       ```
   
 * Does this solve your error?
 * Guido
 *  Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/)
 * (@dimalifragis)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17107829)
 * I will and update here.
 *  Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/)
 * (@dimalifragis)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17108283)
 * That change seems to fix the issue.
 *  Plugin Author [Guido](https://wordpress.org/support/users/guido07111975/)
 * (@guido07111975)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17108383)
 * Thanks, I will update plugin today. 
   I may remove the newly added cookie feature
   again, because in some cases it may cause a conflict with other plugins and I
   don’t have control over that. This makes VS Contact Form less stable.
 * Guido
 *  Plugin Author [Guido](https://wordpress.org/support/users/guido07111975/)
 * (@guido07111975)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17119267)
 * Hi again [@dimalifragis](https://wordpress.org/support/users/dimalifragis/)
 * Did your warning/error only include a reference to my plugin or was there a reference
   to another plugin or theme as well?
 * Guido
 *  Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/)
 * (@dimalifragis)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17119650)
 * Hi, no the error pointed only to your plugin.
 *  Plugin Author [Guido](https://wordpress.org/support/users/guido07111975/)
 * (@guido07111975)
 * [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17122787)
 * Thanks, thought about it some more and will not add cookie again. Besides your
   issue there’s also GDPR (privacy) and adblockers that may cause problems.
 * Guido

Viewing 11 replies - 1 through 11 (of 11 total)

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

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 * 11 replies
 * 2 participants
 * Last reply from: [Guido](https://wordpress.org/support/users/guido07111975/)
 * Last activity: [2 years, 8 months ago](https://wordpress.org/support/topic/php-warning-cannot-modify-header-information-26/#post-17122787)
 * Status: resolved