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