Fatal error: Uncaught Error: Class "Bitrix\UI\EntitySelector\BaseProvider" not found in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\integration\ui\entityselector\roomprovider.php:6 Stack trace: #0 {main} thrown in D:\ktt\ttepla.com\public_html\bitrix\modules\calendar\lib\integration\ui\entityselector\roomprovider.php on line 6