Title: Warning: Cannot modify header information PHP error
Last modified: August 30, 2016

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# Warning: Cannot modify header information PHP error

 *  Resolved [mocreate](https://wordpress.org/support/users/mocreate/)
 * (@mocreate)
 * [10 years, 8 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/)
 * Using the latest version of the plugin and WordPress, I’m getting this error 
   when updating posts. The pages still work, but every update I get a screen with
   this message:
 * >  Warning: Cannot modify header information – headers already sent by (output
   > started at /home/content/p3pnexwpnas10_data02/63/2553263/html/wp-content/plugins/
   > advanced-iframe/includes/advanced-iframe-main-read-config.php:404) in /home/
   > content/p3pnexwpnas10_data02/63/2553263/html/wp-admin/post.php on line 242
   > Warning: Cannot modify header information – headers already sent by (output
   > started at /home/content/p3pnexwpnas10_data02/63/2553263/html/wp-content/plugins/
   > advanced-iframe/includes/advanced-iframe-main-read-config.php:404) in /home/
   > content/p3pnexwpnas10_data02/63/2553263/html/wp-includes/pluggable.php on line
   > 1207
 * [https://wordpress.org/plugins/advanced-iframe/](https://wordpress.org/plugins/advanced-iframe/)

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

 *  Plugin Author [mdempfle](https://wordpress.org/support/users/mdempfle/)
 * (@mdempfle)
 * [10 years, 8 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535691)
 * I’ll check and let you know…
 *  Plugin Author [mdempfle](https://wordpress.org/support/users/mdempfle/)
 * (@mdempfle)
 * [10 years, 8 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535694)
 * There where some spaces which should not be at the end of this file.
    I removed
   it and updated the download. Please get the new version.
 * Best, Michael
 *  Thread Starter [mocreate](https://wordpress.org/support/users/mocreate/)
 * (@mocreate)
 * [10 years, 8 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535695)
 * Is it still version 6.5.4 or will it be posted as a newer version? Many thank
   yous for looking into it.
 *  Plugin Author [mdempfle](https://wordpress.org/support/users/mdempfle/)
 * (@mdempfle)
 * [10 years, 8 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535697)
 * Now it shows version 6.5.5 ;).
    I forgot to update the version info in the main
   file…
 *  Thread Starter [mocreate](https://wordpress.org/support/users/mocreate/)
 * (@mocreate)
 * [10 years, 8 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535698)
 * Excellent! Thank you!!
 *  [Puuma69](https://wordpress.org/support/users/puuma69/)
 * (@puuma69)
 * [10 years, 7 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535862)
 * I have this error Warning: Cannot modify header information – headers already
   sent by (output started at /var/www/customers/lagooncharterfi/public_html/wp-
   includes/functions.php:1) in /var/www/customers/lagooncharterfi/public_html/wp-
   login.php on line 425
 * I tried to fix functions.php, line 1 but there is no wrong codes.Can someone 
   help?
 *  Plugin Author [mdempfle](https://wordpress.org/support/users/mdempfle/)
 * (@mdempfle)
 * [10 years, 7 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535863)
 * Where is the relation to this plugin? There are only files that don’t belong 
   to advanced iframe.
    Check the file functions.php and check if it is saved in
   utf-8 without BOM. Maybe this happened if you did some changes in this file.
 * Best, Michael
 *  [Puuma69](https://wordpress.org/support/users/puuma69/)
 * (@puuma69)
 * [10 years, 7 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535866)
 * That worked.Thanks

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

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 * 8 replies
 * 3 participants
 * Last reply from: [Puuma69](https://wordpress.org/support/users/puuma69/)
 * Last activity: [10 years, 7 months ago](https://wordpress.org/support/topic/warning-cannot-modify-header-information-php-error/#post-6535866)
 * Status: resolved