Title: [Plugin: Alkivia Open Community] “Cannot modify header information…” error
Last modified: August 19, 2016

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# [Plugin: Alkivia Open Community] “Cannot modify header information…” error

 *  [liesl89](https://wordpress.org/support/users/liesl89/)
 * (@liesl89)
 * [16 years, 6 months ago](https://wordpress.org/support/topic/plugin-alkivia-open-community-cannot-modify-header-information-error/)
 * After upgrading to the latest version of Alkivia Open Community, I’ve been getting
   this error. At first I thought it was another plugin, Sidebar Login, but it’s
   Alkivia that is causing it because it even pops up after activating/deactivating
   a plugin. Here’s the error:
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/username/public_html/wp-content/plugins/alkivia/components/gallery/class.
   gallery.php:1)
 * Please let me know if it’s possible to fix. Thank you.
 * [http://wordpress.org/extend/plugins/alkivia/](http://wordpress.org/extend/plugins/alkivia/)

Viewing 4 replies - 1 through 4 (of 4 total)

 *  Thread Starter [liesl89](https://wordpress.org/support/users/liesl89/)
 * (@liesl89)
 * [16 years, 6 months ago](https://wordpress.org/support/topic/plugin-alkivia-open-community-cannot-modify-header-information-error/#post-1257653)
 * I also tried downgrading to the previous version of Alkivia that I had, and the
   error was still there. It also shows up on top of the page when I’m browsing 
   around the WP dashboard.
 *  Thread Starter [liesl89](https://wordpress.org/support/users/liesl89/)
 * (@liesl89)
 * [16 years, 6 months ago](https://wordpress.org/support/topic/plugin-alkivia-open-community-cannot-modify-header-information-error/#post-1257837)
 * I just realized I cut part of the error off. Sorry.
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/username/public_html/wp-content/plugins/alkivia/components/gallery/class.
   gallery.php:1) in /home/username/public_html/wp-content/plugins/sidebar-login/
   sidebar-login.php on line 311
 * When I use Alkivia with the Sidebar Login plugin off, it works fine except the
   error appears again when I edit a theme template file for example (Warning: Cannot
   modify header information – headers already sent by (output started at /home/
   username/public_html/wp-content/plugins/alkivia/components/gallery/class.gallery.
   php:1) in /home/username/public_html/wp-admin/theme-editor.php on line 69), and
   also when I active/deactive any plugin (Warning: Cannot modify header information–
   headers already sent by (output started at /home/username/public_html/wp-content/
   plugins/alkivia/components/gallery/class.gallery.php:1) in /home/username/public_html/
   wp-includes/pluggable.php on line 865). Right now I had to deactivate AOC in 
   order to get the error to disappear.
 * I hope this can be fixed soon. Thanks in advance.
 *  [Txanny](https://wordpress.org/support/users/txanny/)
 * (@txanny)
 * [16 years, 6 months ago](https://wordpress.org/support/topic/plugin-alkivia-open-community-cannot-modify-header-information-error/#post-1257972)
 * Looks like when editing a template file, you introduced a blank space after the
   closing or before the opening PHP tags. <?php ?>
 * I would recommend to never use the closing tag at the end of file, as it is not
   required and avoiding it would prevent some problems. Some editors introduce 
   a line break at the end of the file witch causes this.
 *  Thread Starter [liesl89](https://wordpress.org/support/users/liesl89/)
 * (@liesl89)
 * [16 years, 6 months ago](https://wordpress.org/support/topic/plugin-alkivia-open-community-cannot-modify-header-information-error/#post-1257973)
 * Oh ok. I re-installed it and carefully edited the templates and it’s working 
   fine now. Thank you!

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘[Plugin: Alkivia Open Community] “Cannot modify header information…” 
error’ is closed to new replies.

 * 4 replies
 * 2 participants
 * Last reply from: [liesl89](https://wordpress.org/support/users/liesl89/)
 * Last activity: [16 years, 6 months ago](https://wordpress.org/support/topic/plugin-alkivia-open-community-cannot-modify-header-information-error/#post-1257973)
 * Status: not resolved

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