Title: “Warning: Cannot modify header information”
Last modified: January 2, 2020

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# “Warning: Cannot modify header information”

 *  [PITCHEDsenses](https://wordpress.org/support/users/ericodl/)
 * (@ericodl)
 * [6 years, 5 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-201/)
 * When I duplicate a completed order, it’s working but I always get this message
   right after it loads the page. What could be the issue?
 * Warning: Cannot modify header information – headers already sent by (output started
   at /wp-content/plugins/wc-duplicate-order/classes/class-clone-order.php:37) in/
   wp-includes/functions.php on line 6029
 * Warning: Cannot modify header information – headers already sent by (output started
   at /wp-content/plugins/wc-duplicate-order/classes/class-clone-order.php:37) in/
   wp-admin/includes/misc.php on line 1252
 * Warning: Cannot modify header information – headers already sent by (output started
   at /wp-content/plugins/wc-duplicate-order/classes/class-clone-order.php:37) in/
   wp-admin/admin-header.php on line 9
 * With best regards
    Eric

Viewing 1 replies (of 1 total)

 *  Plugin Author [Jamie Gill](https://wordpress.org/support/users/patchgill/)
 * (@patchgill)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-201/#post-12718008)
 * Hi Eric,
 * I am unsure why this would be as the duplication has no problems this end, perhaps
   a conflict of another plugin?
 * Can you change theme to a default wordpress one and make sure you are updated
   to the latest woocommerce, disable all other plugins and give this a test please?
 * Many Thanks
    Jamie

Viewing 1 replies (of 1 total)

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

 * ![](https://ps.w.org/wc-duplicate-order/assets/icon-128x128.png?rev=1494762)
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## Tags

 * [PHP Warning](https://wordpress.org/support/topic-tag/php-warning/)

 * 1 reply
 * 2 participants
 * Last reply from: [Jamie Gill](https://wordpress.org/support/users/patchgill/)
 * Last activity: [6 years, 1 month ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-201/#post-12718008)
 * Status: not resolved