Fatal error: Uncaught Error: Class "WP_Customize_Setting" not found in /home/.sites/10/site5622882/web/buschka/ikt5-2022-23/patrick_kohl/upcyling/wp-includes/customize/class-wp-customize-custom-css-setting.php:19
Stack trace:
#0 {main}
  thrown in /home/.sites/10/site5622882/web/buschka/ikt5-2022-23/patrick_kohl/upcyling/wp-includes/customize/class-wp-customize-custom-css-setting.php on line 19