Title: Undefined Index & Cannot modify header information Errors
Last modified: June 5, 2019

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# Undefined Index & Cannot modify header information Errors

 *  Resolved [dreamingfifi](https://wordpress.org/support/users/dreamingfifi/)
 * (@dreamingfifi)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/)
 * One of my users sent me this error:
 * > **Notice:** Undefined index: in **/srv/users/serverpilot/apps/realelvish/public/
   > wp-content/plugins/cleantalk-spam-protect/cleantalk.php** on line **541**
   > **Warning:** Cannot modify header information – headers already sent by (output
   > started at /srv/users/serverpilot/apps/realelvish/public/wp-content/plugins/
   > cleantalk-spam-protect/cleantalk.php:541) in **/srv/users/serverpilot/apps/
   > realelvish/public/wp-content/plugins/cleantalk-spam-protect/cleantalk.php**
   > on line **541**
 * She’s using an android cellphone with Chrome as her browser. I had her clear 
   her history and cache first, but nothing worked until I deactivated the plugin.
 * This happened right after I updated the plugin today, with the update that was
   issued today.
 * On my desktop and my own android phone with chrome, I can’t get the same errors.
 * Any help would be appreciated!

Viewing 7 replies - 1 through 7 (of 7 total)

 *  Thread Starter [dreamingfifi](https://wordpress.org/support/users/dreamingfifi/)
 * (@dreamingfifi)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11609866)
 * More info!
 * It’s only this page [Quenya Name Lists](https://realelvish.net/names/quenya/).
   But, I have no idea what’s wrong with this page, I haven’t found anything different
   about it from any others.
 *  Thread Starter [dreamingfifi](https://wordpress.org/support/users/dreamingfifi/)
 * (@dreamingfifi)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11609933)
 * And some more info!
 * By asking around, I found some more people having the same problems. All with
   different devices and browsers.
 * And, it affects all of the “downstream” pages as well, making access to all of
   the Quenya namelists cut off.
 *  Plugin Author [alexandergull](https://wordpress.org/support/users/alexandergull/)
 * (@alexandergull)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11610421)
 * Hello, [@dreamingfifi](https://wordpress.org/support/users/dreamingfifi/)
 * Thank you for your feedback.
 * I transfer this info to the development group.
 * We will contact you within 2-3 workdays.
 * Write back to us anytime.
 * Be well,
 *  [Safronik](https://wordpress.org/support/users/safronik/)
 * (@safronik)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11610721)
 * Hello,
 * We have fixed this issue. Please, update plugin to latest 5.121.1 version. (You
   could use WordPress plugins page to do this)
 * Contact us if you have any questions.
 *  Thread Starter [dreamingfifi](https://wordpress.org/support/users/dreamingfifi/)
 * (@dreamingfifi)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11612705)
 * Thank you! Everyone is reporting that it works now.
 *  Thread Starter [dreamingfifi](https://wordpress.org/support/users/dreamingfifi/)
 * (@dreamingfifi)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11612710)
 * Let’s just mark this as complete…
 *  Plugin Author [alexandergull](https://wordpress.org/support/users/alexandergull/)
 * (@alexandergull)
 * [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11612756)
 * We are glad the issue is resolved.
 * Come back to us anytime.

Viewing 7 replies - 1 through 7 (of 7 total)

The topic ‘Undefined Index & Cannot modify header information Errors’ is closed 
to new replies.

 * ![](https://ps.w.org/cleantalk-spam-protect/assets/icon-256x256.png?rev=1637702)
 * [Spam protection, Honeypot, Anti-Spam by CleanTalk](https://wordpress.org/plugins/cleantalk-spam-protect/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/cleantalk-spam-protect/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/cleantalk-spam-protect/)
 * [Active Topics](https://wordpress.org/support/plugin/cleantalk-spam-protect/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/cleantalk-spam-protect/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/cleantalk-spam-protect/reviews/)

 * 7 replies
 * 3 participants
 * Last reply from: [alexandergull](https://wordpress.org/support/users/alexandergull/)
 * Last activity: [6 years, 10 months ago](https://wordpress.org/support/topic/undefined-index-cannot-modify-header-information-errors/#post-11612756)
 * Status: resolved