Title: Warning: Cannot modify header information error
Last modified: February 25, 2026

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# Warning: Cannot modify header information error

 *  [braanmcbrutal](https://wordpress.org/support/users/braanmcbrutal/)
 * (@braanmcbrutal)
 * [3 months, 1 week ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-error-2/)
 * Hi Please advise on the following error. WordPress 6.9.1
 * Warning: Cannot modify header information – headers already sent by (output started
   at /usr/www/users/slickmfgbv/wp-content/plugins/zapper-payments/zapper-payments-
   blocks.php:1) in /usr/www/users/slickmfgbv/wp-includes/functions.php on line 
   7181 Warning: Cannot modify header information – headers already sent by (output
   started at /usr/www/users/slickmfgbv/wp-content/plugins/zapper-payments/zapper-
   payments-blocks.php:1) in /usr/www/users/slickmfgbv/wp-admin/admin-header.php
   on line 14

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 * 0 replies
 * 1 participant
 * Last reply from: [braanmcbrutal](https://wordpress.org/support/users/braanmcbrutal/)
 * Last activity: [3 months, 1 week ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-error-2/)
 * Status: not resolved