Fatal error: Uncaught Error: Class "Bitrix\Calendar\ICal\Basic\Observance" not found in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\ical\builder\standardobservances.php:9 Stack trace: #0 {main} thrown in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\ical\builder\standardobservances.php on line 9