[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SELECT 
	`catalog_catalog_iblock`.`IBLOCK_ID` AS `IBLOCK_ID`,
	`catalog_catalog_iblock`.`PRODUCT_IBLOCK_ID` AS `PRODUCT_IBLOCK_ID`,
	`catalog_catalog_iblock`.`SKU_PROPERTY_ID` AS `SKU_PROPERTY_ID`,
	`catalog_catalog_iblock_iblock`.`VERSION` AS `VERSION`,
	`catalog_catalog_iblock_iblock`.`ID` AS `UALIAS_0`
FROM `b_catalog_iblock` `catalog_catalog_iblock` 
INNER JOIN `b_iblock` `catalog_catalog_iblock_iblock` ON `catalog_catalog_iblock`.`IBLOCK_ID` = `catalog_catalog_iblock_iblock`.`ID`
WHERE `catalog_catalog_iblock`.`PRODUCT_IBLOCK_ID` = 19
/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/modules/catalog/general/catalog_sku.php:143
#5: CAllCatalogSku::GetInfoByProductIBlock(integer)
	/home/bitrix/www/bitrix/modules/iblock/lib/propertyindex/facet.php:45
#6: Bitrix\Iblock\PropertyIndex\Facet->__construct(string)
	/home/bitrix/www/bitrix/modules/iblock/lib/propertyindex/querybuilder.php:28
#7: Bitrix\Iblock\PropertyIndex\QueryBuilder->__construct(string)
	/home/bitrix/www/bitrix/modules/iblock/classes/general/iblockelement.php:657
#8: CAllIBlockElement->MkFilter(array, array, array)
	/home/bitrix/www/bitrix/modules/iblock/classes/general/iblockelement.php:3088
#9: CAllIBlockElement->PrepareGetList(array, array, array, string, array, array, NULL, NULL, array, boolean, string, array, array, array)
	/home/bitrix/www/bitrix/modules/iblock/classes/mysql/iblockelement.php:343
#10: CIBlockElement->prepareSql(array, array, boolean, array)
	/home/bitrix/www/bitrix/modules/iblock/classes/mysql/iblockelement.php:662
#11: CIBlockElement::GetList(array, array, boolean, array, array)
	/home/bitrix/www/local/components/tesslab/location.cities/component.php:304
#12: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:605
#13: CBitrixComponent->__includeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:664
#14: CBitrixComponent->includeComponent(string, array, boolean)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1039
#15: CAllMain->IncludeComponent(string, string, array, boolean)
	/home/bitrix/www/local/templates/expert24_default/header.php:182
#16: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_after.php:106
#17: require(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:11
#18: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#19: require(string)
	/home/bitrix/www/ua/catalog/index.php:2
#20: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#21: include_once(string)
	/home/bitrix/www/bitrix/urlrewrite.php:2