Title: Customize/Additional CSS section doesn’t work
Last modified: May 11, 2019

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# Customize/Additional CSS section doesn’t work

 *  Resolved [nicktirdea](https://wordpress.org/support/users/nicktirdea/)
 * (@nicktirdea)
 * [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/)
 * Hello,
 * Few days ago I noticed that I can’t save modifications in “Customize/Additional
   CSS” section. When I try to do it, I receive such message: “Looks like something’s
   gone wrong. Wait a couple seconds, and then try again.”
 * In addition, In Google Chrome console (web developer tools) I see these errors:
   –
   Failed to load resource: the server responded with a status of 406 () – POST 
   [https://my-site.com/wp-admin/admin-ajax.php](https://my-site.com/wp-admin/admin-ajax.php)
   406
 * I don’t know surely what is the cause of this issue. I tried to disable plugins
   which I recently installed/updated, but it doesn’t work. May this issue be related
   to WordPress 5.2 update? If yes, tell me please how to solve it.
 * Thank you,
    Nick
    -  This topic was modified 7 years ago by [nicktirdea](https://wordpress.org/support/users/nicktirdea/).

Viewing 5 replies - 1 through 5 (of 5 total)

 *  [Stef](https://wordpress.org/support/users/serafinnyc/)
 * (@serafinnyc)
 * [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/#post-11521113)
 * You most likely have a JS issue in your header file from whatever theme you are
   using. Try and revert to a default theme and test. If it works then you know 
   you added something to the header or something in the header is breaking this.
 *  Thread Starter [nicktirdea](https://wordpress.org/support/users/nicktirdea/)
 * (@nicktirdea)
 * [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/#post-11521231)
 * Yes, it is a theme issue. I changed the theme to default one and it disappeared.
   Thank you for your help. Will check my theme.
 *  [Stef](https://wordpress.org/support/users/serafinnyc/)
 * (@serafinnyc)
 * [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/#post-11521238)
 * Great. So now go to wp-config and turn on debug mode and revert back to the theme
   you were using to view any errors that may display.
 *  Thread Starter [nicktirdea](https://wordpress.org/support/users/nicktirdea/)
 * (@nicktirdea)
 * [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/#post-11521347)
 * Thank you for instructions. I think I found the error:
 * [11-May-2019 21:19:34 UTC] PHP Notice: wc_ajax_headers cannot set headers – headers
   already sent by <my site> /public_html/wp-includes/functions.php on line 4773
   in <my site> /public_html/wp-content/plugins/woocommerce/includes/class-wc-ajax.
   php on line 67
 *  [Stef](https://wordpress.org/support/users/serafinnyc/)
 * (@serafinnyc)
 * [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/#post-11521363)
 * This is confirming what I stated initially. What was modified in your theme’s
   header.php file lately? That’s where your issue is. It’s conflicting with WP &
   WC.

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘Customize/Additional CSS section doesn’t work’ is closed to new replies.

## Tags

 * [additional css](https://wordpress.org/support/topic-tag/additional-css/)
 * [wordpress 5.2](https://wordpress.org/support/topic-tag/wordpress-5-2/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 5 replies
 * 2 participants
 * Last reply from: [Stef](https://wordpress.org/support/users/serafinnyc/)
 * Last activity: [7 years ago](https://wordpress.org/support/topic/customize-additional-css-section-doesnt-work/#post-11521363)
 * Status: resolved

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