[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SELECT 
	`iblock_iblock_site`.`IBLOCK_ID` AS `IBLOCK_ID`,
	`iblock_iblock_site`.`SITE_ID` AS `UALIAS_0`,
	`iblock_iblock_site_iblock`.`ID` AS `UALIAS_1`
FROM `b_iblock_site` `iblock_iblock_site` 
LEFT JOIN `b_iblock` `iblock_iblock_site_iblock` ON `iblock_iblock_site`.`IBLOCK_ID` = `iblock_iblock_site_iblock`.`ID`
WHERE `iblock_iblock_site`.`IBLOCK_ID` = 4
AND `iblock_iblock_site`.`SITE_ID` = 'e1'
AND `iblock_iblock_site_iblock`.`ACTIVE` = 'Y'
/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:137
#0: Bitrix\Main\DB\MysqliConnection->queryInternal(string, array, NULL)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:330
#1: Bitrix\Main\DB\Connection->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php:3306
#2: Bitrix\Main\ORM\Query\Query->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php:817
#3: Bitrix\Main\ORM\Query\Query->exec()
	/home/bitrix/www/bitrix/modules/main/lib/orm/data/datamanager.php:500
#4: Bitrix\Main\ORM\Data\DataManager::getList(array)
	/home/bitrix/www/bitrix/components/bitrix/catalog.section.list/component.php:80
#5: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:605
#6: CBitrixComponent->__includeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:664
#7: CBitrixComponent->includeComponent(string, array, object)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1039
#8: CAllMain->IncludeComponent(string, string, array, object, array)
	/home/bitrix/www/local/templates/expert24_default/components/tesslab/catalog/main/section_vertical.php:142
#9: include(string)
	/home/bitrix/www/local/templates/expert24_default/components/tesslab/catalog/main/section.php:78
#10: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:789
#11: CBitrixComponentTemplate->__IncludePHPTemplate(array, array, string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:884
#12: CBitrixComponentTemplate->IncludeTemplate(array)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:746
#13: CBitrixComponent->showComponentTemplate()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:694
#14: CBitrixComponent->includeComponentTemplate(string)
	/home/bitrix/www/local/components/tesslab/catalog/component.php:197
#15: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:605
#16: CBitrixComponent->__includeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:664
#17: CBitrixComponent->includeComponent(string, array, boolean)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1039
#18: CAllMain->IncludeComponent(string, string, array, boolean)
	/home/bitrix/www/ua/catalog/index.php:530
#19: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#20: include_once(string)
	/home/bitrix/www/bitrix/urlrewrite.php:2