Title: Error after upgrading: Warning: Cannot modify header information
Last modified: August 20, 2016

---

# Error after upgrading: Warning: Cannot modify header information

 *  [njeshg](https://wordpress.org/support/users/njeshg/)
 * (@njeshg)
 * [15 years ago](https://wordpress.org/support/topic/error-after-upgrading-warning-cannot-modify-header-information/)
 * I recently updated my wordpress to 3.1 (3 days ago) and now my site is down this
   is the error I’m getting:
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/shawn02/public_html/wp-content/themes/shawn/custom/custom_functions.
   php:1) in /home/shawn02/public_html/wp-includes/pluggable.php on line 897
 * I have read previous threads with similar issues but not no avail nothing is 
   working… can someone please help me??

Viewing 1 replies (of 1 total)

 *  [govpatel](https://wordpress.org/support/users/govpatel/)
 * (@govpatel)
 * [15 years ago](https://wordpress.org/support/topic/error-after-upgrading-warning-cannot-modify-header-information/#post-2093589)
 * looks like you did not upgrade properly try and replace wp-includes folder do
   not over write.

Viewing 1 replies (of 1 total)

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

## Tags

 * [modify header](https://wordpress.org/support/topic-tag/modify-header/)
 * [upgrade](https://wordpress.org/support/topic-tag/upgrade/)

 * In: [Installing WordPress](https://wordpress.org/support/forum/installation/)
 * 1 reply
 * 2 participants
 * Last reply from: [govpatel](https://wordpress.org/support/users/govpatel/)
 * Last activity: [15 years ago](https://wordpress.org/support/topic/error-after-upgrading-warning-cannot-modify-header-information/#post-2093589)
 * Status: not resolved

## Topics

### Topics with no replies

### Non-support topics

### Resolved topics

### Unresolved topics

### All topics