[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`
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` = 28
/home/u47009/sth96.ru/www/bitrix/modules/main/lib/db/mysqliconnection.php:138
#0: Bitrix\Main\DB\MysqliConnection->queryInternal(string, array, NULL)
	/home/u47009/sth96.ru/www/bitrix/modules/main/lib/db/connection.php:329
#1: Bitrix\Main\DB\Connection->query(string)
	/home/u47009/sth96.ru/www/bitrix/modules/main/lib/entity/query.php:1753
#2: Bitrix\Main\Entity\Query->query(string)
	/home/u47009/sth96.ru/www/bitrix/modules/main/lib/entity/query.php:454
#3: Bitrix\Main\Entity\Query->exec()
	/home/u47009/sth96.ru/www/bitrix/modules/main/lib/entity/datamanager.php:230
#4: Bitrix\Main\Entity\DataManager::getList(array)
	/home/u47009/sth96.ru/www/bitrix/modules/catalog/general/catalog_sku.php:144
#5: CAllCatalogSKU::GetInfoByProductIBlock(integer)
	/home/u47009/sth96.ru/www/bitrix/modules/iblock/lib/propertyindex/facet.php:45
#6: Bitrix\Iblock\PropertyIndex\Facet->__construct(string)
	/home/u47009/sth96.ru/www/bitrix/modules/iblock/lib/propertyindex/querybuilder.php:28
#7: Bitrix\Iblock\PropertyIndex\QueryBuilder->__construct(string)
	/home/u47009/sth96.ru/www/bitrix/modules/iblock/classes/general/iblockelement.php:639
#8: CAllIBlockElement::MkFilter(array, array, array)
	/home/u47009/sth96.ru/www/bitrix/modules/iblock/classes/general/iblockelement.php:3011
#9: CAllIBlockElement::PrepareGetList(array, array, NULL, boolean, array, string, array, array, NULL, NULL, array, boolean, string, array, array, array, NULL, array, NULL, array, array, NULL)
	/home/u47009/sth96.ru/www/bitrix/modules/iblock/classes/mysql/iblockelement.php:361
#10: CIBlockElement::GetList(array, array, boolean, array, array)
	/home/u47009/sth96.ru/www/katalog/spetstekhnika/sitemap_items_katalog.php:16