Fatal error: Uncaught Error: Call to undefined function add_action() in /home/antenaserwis/public_html/satserwis/wp-content/plugins/jetpack/modules/widgets/twitter-timeline.php:25
Stack trace:
#0 {main}
thrown in /home/antenaserwis/public_html/satserwis/wp-content/plugins/jetpack/modules/widgets/twitter-timeline.php on line 25