Fatal error: Uncaught Error: Class "Bitrix\Calendar\ICal\MailInvitation\AttachmentManager" not found in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\ical\mailinvitation\attachmentcancelmanager.php:18 Stack trace: #0 {main} thrown in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\ical\mailinvitation\attachmentcancelmanager.php on line 18