Fatal error: Uncaught Error: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "bbloomer_woocommerce_holiday_mode" not found or invalid function name
in /homepages/24/d25460770/htdocs/sauschwaenzlebahn.de/wp-includes/class-wp-hook.php on line 287

Call stack:

1. WP_Hook::apply_filters()
   wp-includes/class-wp-hook.php:311
2. WP_Hook::do_action()
   wp-includes/plugin.php:484
3. do_action()
   wp-settings.php:557
4. require_once()
   wp-config.php:89
5. require_once()
   wp-load.php:37
6. require_once()
   wp-blog-header.php:13
7. require()
   index.php:17