Title: Fatal error; Undefined Function
Last modified: May 9, 2018

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# Fatal error; Undefined Function

 *  Resolved [costi123](https://wordpress.org/support/users/costi123/)
 * (@costi123)
 * [8 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/)
 * Fatal error: Call to undefined function is_user_logged_in() in /home/user/public_html/
   domain/wp-includes/post.php on line 2191.
 * I like this plugin and is extremely useful. I’ve tested it since its beginning
   on WordPress. BUT, this error appeared for the first time on my development site
   after installed GDPR plugin. To fix this, I have to go to the back-end, to delete
   the GDPR plugin in order to access my website. And then I’ve installed it again.
 * Any solution to this, please?

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

 *  Plugin Author [Fernando Claussen](https://wordpress.org/support/users/fclaussen/)
 * (@fclaussen)
 * [8 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10262651)
 * Hi [@costi123](https://wordpress.org/support/users/costi123/),
    Unfortunately,
   this error message is not indicating a file and line in the plugin. It makes 
   it nearly impossible to figure out the problem like this.
 * Do you happen to have a stack trace?
 *  [benoitmarie9](https://wordpress.org/support/users/benoitmarie9/)
 * (@benoitmarie9)
 * [8 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10267315)
 * Hi guys,
 * I faced an identical problem when saving the settings page:
 * “Fatal error: Call to undefined function boolval() in /home/content/69/6589069/
   html/beta/tsint3/wp-content/plugins/gdpr/admin/class-gdpr-admin.php on line 254”.
 * It’s pointing to a file in the plugin but I don’t know what to do about it.
 * Thanks in advance for the help
    -  This reply was modified 8 years, 1 month ago by [benoitmarie9](https://wordpress.org/support/users/benoitmarie9/).
 *  Plugin Author [Anthony Moore](https://wordpress.org/support/users/amooreto/)
 * (@amooreto)
 * [8 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10267324)
 * Hi [@benoitmarie9](https://wordpress.org/support/users/benoitmarie9/), that is
   a different error message.
 * Your website needs to be running off of PHP version 5.6 or higher. You will need
   to ask your hosting provider to update your PHP settings.
 *  [benoitmarie9](https://wordpress.org/support/users/benoitmarie9/)
 * (@benoitmarie9)
 * [8 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10267331)
 * Thanks [@amooreto](https://wordpress.org/support/users/amooreto/) 🙂
    -  This reply was modified 8 years, 1 month ago by [benoitmarie9](https://wordpress.org/support/users/benoitmarie9/).
 *  [keenekei](https://wordpress.org/support/users/keenekei/)
 * (@keenekei)
 * [8 years ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10318885)
 * Hi, great plug-in I THINK… but I can’t get it to work! Every time I change a 
   setting (during set up process) and Save, I get this Fatal Error on line 254 
   message:
    Fatal error: Call to undefined function boolval() in /home/ho3aio346ld8/
   public_html/wp-content/plugins/gdpr/admin/class-gdpr-admin.php on line 254
 * Checked with my hosting provider re PHP version and this is it: 5.6.39-cll-lve–
   MySQL Community Server (GPL)
 * thanks for any help you can provide!
 *  Plugin Author [Fernando Claussen](https://wordpress.org/support/users/fclaussen/)
 * (@fclaussen)
 * [8 years ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10318943)
 * This function is actually for 5.5 as stated in the PHP documentation [http://php.net/manual/en/function.boolval.php](http://php.net/manual/en/function.boolval.php)
 * If you are getting this error, your PHP version is below that.
 *  [keenekei](https://wordpress.org/support/users/keenekei/)
 * (@keenekei)
 * [8 years ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10319529)
 * Fernando, you were absolutely correct — thank you!! I just got off the phone 
   with my hosting provider and updated the PHP to version 5.6. Everything’s working
   great now, thanks again for an awesome plugin!
 *  Plugin Author [Fernando Claussen](https://wordpress.org/support/users/fclaussen/)
 * (@fclaussen)
 * [8 years ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10320108)
 * You are welcome 🙂

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

The topic ‘Fatal error; Undefined Function’ is closed to new replies.

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## Tags

 * [fatal error message](https://wordpress.org/support/topic-tag/fatal-error-message/)

 * 8 replies
 * 5 participants
 * Last reply from: [Fernando Claussen](https://wordpress.org/support/users/fclaussen/)
 * Last activity: [8 years ago](https://wordpress.org/support/topic/fatal-error-undefined-function-9/#post-10320108)
 * Status: resolved