Title: Warning: Cannot modify header information error message
Last modified: August 21, 2016

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# Warning: Cannot modify header information error message

 *  [Teresa Lo](https://wordpress.org/support/users/teresa_lo/)
 * (@teresa_lo)
 * [12 years, 4 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-error-message/)
 * After upgrading to WP 3.8, I noticed that a public the page with [catlist] shortcode
   displayed an error message:
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/invivoan/public_html/wp-content/themes/simplebusiness_v1_1/header.php:
   2) in /home/invivoan/public_html/wp-includes/pluggable.php on line 896
 * In case the problem was with the theme, I loaded the new Twenty Fourteen theme
   and the error message is:
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/invivoan/public_html/wp-content/themes/twentyfourteen/header.php:13)
   in /home/invivoan/public_html/wp-includes/pluggable.php on line 896
 * When I take away the sections with the [catlist] shortcode, the page loads.
 * Yet somehow, the page with [catlist] loaded fine if logged in as admin. In case
   it matters, site access is controlled uses the Member Access plugin Version 1.1.6
   by Chris Abernethy.
 * [http://wordpress.org/plugins/list-category-posts/](http://wordpress.org/plugins/list-category-posts/)

Viewing 1 replies (of 1 total)

 *  Plugin Author [Fernando Briano](https://wordpress.org/support/users/fernandobt/)
 * (@fernandobt)
 * [12 years, 4 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-error-message/#post-4431429)
 * This is really strange, did you try disabling all of the plugins and enabling
   them one by one to see which one is the cause of this error? I wasn’t able to
   reproduce the bug on my side, if any other user is having this issue please report
   it here.

Viewing 1 replies (of 1 total)

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

 * ![](https://ps.w.org/list-category-posts/assets/icon-256x256.png?rev=2517221)
 * [List category posts](https://wordpress.org/plugins/list-category-posts/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/list-category-posts/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/list-category-posts/)
 * [Active Topics](https://wordpress.org/support/plugin/list-category-posts/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/list-category-posts/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/list-category-posts/reviews/)

 * 1 reply
 * 2 participants
 * Last reply from: [Fernando Briano](https://wordpress.org/support/users/fernandobt/)
 * Last activity: [12 years, 4 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-error-message/#post-4431429)
 * Status: not resolved