unknownentityexception.php

См. документацию.

<?php
 
namespace Bitrix\Main\Access\Filter;
 
use Bitrix\Main\SystemException;

class UnknownEntityException extends SystemException
{
    public function __construct(string $entity, AccessFilter $accessFilter)
    {
        $accessFilterName = get_class($accessFilter);
 
        parent::__construct(
            "Unknown entity '{$entity}' for access filter '{$accessFilterName}'"
        );
    }
}