Fatal error: Uncaught Error: Class "Bitrix\Calendar\Core\Base\Collection" not found in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\core\section\sectioncollection.php:5 Stack trace: #0 {main} thrown in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\core\section\sectioncollection.php on line 5