error(s) from Gospelkoor Miracles

Message Couldn't find Calendar\Calendar with ID=53
Script (line) /home/sites/site46794/web/golive/classes/GOlib/ActiveRecord/lib/Model.php 1471
Type Exception
Time
Backtrace
PHPActiveRecord\Model::find on 51 in /home/sites/site46794/web/classes/view/Kalender.class.php
Kalender->showSingleItem on 17 in /home/sites/site46794/web/classes/view/Kalender.class.php
Kalender->__construct on 47 in /home/sites/site46794/web/golive/classes/GOlib/GOCore.class.php
GOCore->loadPage on 349 in /home/sites/site46794/web/golive/classes/GOlib/GOConfig.class.php
GOConfig->initialize on 14 in /home/sites/site46794/web/index.php
Variables
$_REQUEST
call
optredens/komende-optredens/53
$_SESSION
$_SERVER
REMOTE_ADDR
3.235.65.91
USER AGENT
CCBot/2.0 (https://commoncrawl.org/faq/)