Title: Theme Preview – Warning: Cannot modify header information
Last modified: August 22, 2016

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# Theme Preview – Warning: Cannot modify header information

 *  [BookClubReader](https://wordpress.org/support/users/bookclubreader/)
 * (@bookclubreader)
 * [11 years, 8 months ago](https://wordpress.org/support/topic/theme-preview-warning-cannot-modify-header-information/)
 * I am receiving the following error message when previewing themes
 * >  Warning: Cannot modify header information – headers already sent by (output
   > started at /home/example/public_html/wp-content/plugins/shareaholic/utilities.
   > php:1020) in /home/example/public_html/wp-includes/option.php on line 750
   > Warning: Cannot modify header information – headers already sent by (output
   > started at /home/example/public_html/wp-content/plugins/shareaholic/utilities.
   > php:1020) in /home/example/public_html/wp-includes/option.php on line 751
 * I am running a multisite network using WP 4.0. I have disabled all plugins except
   Shareaholic to test the theme previewer. It still displays the error as the theme
   preview loads.
 * Any ideas on how to fix this?
 * [https://wordpress.org/plugins/shareaholic/](https://wordpress.org/plugins/shareaholic/)

Viewing 1 replies (of 1 total)

 *  [keeneyemedia](https://wordpress.org/support/users/keeneyemedia/)
 * (@keeneyemedia)
 * [11 years, 3 months ago](https://wordpress.org/support/topic/theme-preview-warning-cannot-modify-header-information/#post-5351462)
 * +1
 * I’ve got the exact same setup with multisite and the same errors.

Viewing 1 replies (of 1 total)

The topic ‘Theme Preview – Warning: Cannot modify header information’ is closed 
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## Tags

 * [warning](https://wordpress.org/support/topic-tag/warning/)

 * 1 reply
 * 2 participants
 * Last reply from: [keeneyemedia](https://wordpress.org/support/users/keeneyemedia/)
 * Last activity: [11 years, 3 months ago](https://wordpress.org/support/topic/theme-preview-warning-cannot-modify-header-information/#post-5351462)
 * Status: not resolved