Fatal error: Uncaught Error: Call to a member function add_panel() on null in /home/wmichal67/public_html/lekcjatest-1v-mw/wp-content/themes/sydney/inc/integrations/lifter/customize.php:9 Stack trace: #0 {main} thrown in /home/wmichal67/public_html/lekcjatest-1v-mw/wp-content/themes/sydney/inc/integrations/lifter/customize.php on line 9