Title: Cannot modify header information in version 1.17.4 Last modified: August 21, 2016 --- # Cannot modify header information in version 1.17.4 * [Snorvarg](https://wordpress.org/support/users/snorvarg/) * (@snorvarg) * [12 years, 7 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-in-version-1174/) * Hello. Thank you for a good guestbook plugin. I got everything to work, akismet, captcha. * Only problem is this, everytime I save a setting in DMSGuestbook settings, the plugin produces a ‘Cannot modify header information’ warning, see below. It seem to be a collision between nextgen-gallery and dmsguestbook, so I really don’t know which forum I should post this in! * It does not break anything however, at least nothing I can find. * `Warning: Cannot modify header information - headers already sent by (output started at /siteadress/wp-content/plugins/dmsguestbook/admin.php:3576) in /siteadress/ wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/frame_communication/ class.frame_event_publisher.php on line 74` * [http://wordpress.org/plugins/dmsguestbook/](http://wordpress.org/plugins/dmsguestbook/) Viewing 1 replies (of 1 total) * Plugin Author [DanielSchurter](https://wordpress.org/support/users/danielschurter/) * (@danielschurter) * [12 years, 7 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-in-version-1174/#post-4175751) * You can ignore that. This is an annoying error cause by different reasons, like whitespace, echo call or text format. It’s not really a problem, see [here](http://www.geeklog.net/faqman/index.php?op=view&t=38). * If you don’t like to dive into the haystack searching the needle, deactivate this message by adding following line at the beginning of admin.php (after