Title: PHP 8+ Undefined Variable Error
Last modified: March 24, 2026

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# PHP 8+ Undefined Variable Error

 *  [NetzzJD](https://wordpress.org/support/users/netzzjd/)
 * (@netzzjd)
 * [2 months, 1 week ago](https://wordpress.org/support/topic/php-8-undefined-variable-error/)
 * Getting this in server error logs: 
   PHP Warning: Undefined variable $common_filter_id
   in /wp-content/plugins/graphina-elementor-charts-and-graphs/templates/graphina-
   apex-charts/pie-chart.php on line 15
 * Correctly defining that variable above this line clears the warning.

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 * 0 replies
 * 1 participant
 * Last reply from: [NetzzJD](https://wordpress.org/support/users/netzzjd/)
 * Last activity: [2 months, 1 week ago](https://wordpress.org/support/topic/php-8-undefined-variable-error/)
 * Status: not resolved