Title: Child Theme functions.php breaks admin
Last modified: August 19, 2016

---

# Child Theme functions.php breaks admin

 *  [aarky](https://wordpress.org/support/users/aarky/)
 * (@aarky)
 * [15 years ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/)
 * I am trying to create a child theme. When I include functions.php the site appears
   to work OK, but meta functions (login, logout, update post, etc.) create the 
   Cannot modify header fault, like this:
    `Warning: Cannot modify header information-
   headers already sent by (output started at /homepages/9/d271285184/htdocs/wp-
   content/themes/twentyten-child/functions.php:1) in /homepages/9/d271285184/htdocs/
   wp-login.php on line 354`
 * There is no extra white space in functions.php.
    I have reduced functions.php
   to an open tag, comment, and close tag; the fault persists. The Twenty Ten theme
   exhibits this behavior, as does the Arjuna-X theme. I have disabled all plugins.
   Here’s the functions.php file:
 *     ```
       <?php
       // comment
       ?>
       ```
   
 * I’ve documented what I’ve done on this page:
    [http://arkusinski.net/2011/05/child-wordpress-theme/](http://arkusinski.net/2011/05/child-wordpress-theme/)
 * I’m sure I am missing something obvious. Any help is appreciated.

Viewing 8 replies - 1 through 8 (of 8 total)

 *  [Digital Raindrops](https://wordpress.org/support/users/adeptris/)
 * (@adeptris)
 * [15 years ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061688)
 * Remove the closing tag ?> in functions.php
 * [http://wordpress.org/support/topic/twentyten-child-theme-functionsphp-breaks-login?replies=6](http://wordpress.org/support/topic/twentyten-child-theme-functionsphp-breaks-login?replies=6)
 * > It is the WordPress coding standard to include closing PHP tags on files that
   > are not expected to be edited.
   > That excludes a theme’s functions.php and wp-config.php.
 * HTH
 * David
 *  Thread Starter [aarky](https://wordpress.org/support/users/aarky/)
 * (@aarky)
 * [15 years ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061826)
 * The closing tag does not seem to be the issue here. Removing the closing tag 
   has no effect. functions.php now looks like this:
 *     ```
       <?php
       // comment
       ```
   
 * It does nothing, yet its very existence seems to cause the problem. BTW, I’ve
   tried this with a real function defined, and it makes no difference.
 *  [Chip Bennett](https://wordpress.org/support/users/chipbennett/)
 * (@chipbennett)
 * [15 years ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061828)
 * What about a completely empty `functions.php` file – no tags, comments, or anything?
   Do you still get the same errors?
 *  [Digital Raindrops](https://wordpress.org/support/users/adeptris/)
 * (@adeptris)
 * [15 years ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061832)
 * Reading your post on the website, this happens with other themes and not just
   the twenty ten theme?
 * I would deactivate all plugins and try again, if it is ok activate each plugin
   and test at each point, are there any membership or theme based plugins that 
   may not work with child themes.
 * I have a few child themes with a total of over 7000 [downloads, try one of these](http://digitalraindrops.net/downloads/?category=6)
   then you will know if it is specific to your setup.
 * HTH
 * David
 *  Thread Starter [aarky](https://wordpress.org/support/users/aarky/)
 * (@aarky)
 * [14 years, 10 months ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061995)
 * I’ve come back to this issue. Basically no progress since the last posts, but
   I have a hypothesis. It appears that the child theme works fine for browsing 
   posts, but anytime it tries to write information, such as login, logout, post
   update, or leaving a comment, the problem manifests itself. So I suspect a permissions
   issue, rather than a syntax problem. Can anyone help with what permissions are
   needed by a child theme?
 * I documented details on my blog:
    [http://arkusinski.net/2011/05/child-wordpress-theme/#Summary](http://arkusinski.net/2011/05/child-wordpress-theme/#Summary)
 *  [frantsch](https://wordpress.org/support/users/frantsch/)
 * (@frantsch)
 * [14 years, 10 months ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061998)
 * Same problem here with WordPress 3.2 and the TwentyEleven theme! Any ideas to
   solve this problem are appreciated!
 *  [Chip Bennett](https://wordpress.org/support/users/chipbennett/)
 * (@chipbennett)
 * [14 years, 10 months ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2061999)
 * [@frantsch](https://wordpress.org/support/users/frantsch/): no, really: start
   a new topic. Please stop hijacking other people’s topics.
 *  [frantsch](https://wordpress.org/support/users/frantsch/)
 * (@frantsch)
 * [14 years, 10 months ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2062000)
 * [@chip](https://wordpress.org/support/users/chip/):
    all right, sorry blogpolice!
   I did so now: [wordpress.org/support/topic/functionsphp-will-not-work-with-child-theme](http://wordpress.org/support/topic/functionsphp-will-not-work-with-child-theme)

Viewing 8 replies - 1 through 8 (of 8 total)

The topic ‘Child Theme functions.php breaks admin’ is closed to new replies.

## Tags

 * [cannot modify header](https://wordpress.org/support/topic-tag/cannot-modify-header/)
 * [child theme](https://wordpress.org/support/topic-tag/child-theme/)

 * 8 replies
 * 4 participants
 * Last reply from: [frantsch](https://wordpress.org/support/users/frantsch/)
 * Last activity: [14 years, 10 months ago](https://wordpress.org/support/topic/child-theme-functionsphp-breaks-admin/#post-2062000)
 * Status: not resolved

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