[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` = 2
/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/entity/query.php:3038
#2: Bitrix\Main\Entity\Query->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/entity/query.php:797
#3: Bitrix\Main\Entity\Query->exec()
	/home/bitrix/www/bitrix/modules/main/lib/entity/datamanager.php:290
#4: Bitrix\Main\Entity\DataManager::getList(array)
	/home/bitrix/www/bitrix/modules/catalog/general/catalog_sku.php:143
#5: CAllCatalogSku::GetInfoByProductIBlock(integer)
	/home/bitrix/www/bitrix/components/custom/catalog.smart.filter/class.php:322
#6: CBitrixCatalogSmartFilter->executeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:638
#7: CBitrixComponent->includeComponent(string, array, object)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1041
#8: CAllMain->IncludeComponent(string, string, array, object, array)
	/home/bitrix/www/bitrix/templates/.default/components/bitrix/catalog/catalog_2017/section.php:270
#9: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:720
#10: CBitrixComponentTemplate->__IncludePHPTemplate(array, array, string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:815
#11: CBitrixComponentTemplate->IncludeTemplate(array)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:735
#12: CBitrixComponent->showComponentTemplate()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:683
#13: CBitrixComponent->includeComponentTemplate(string)
	/home/bitrix/www/bitrix/components/bitrix/catalog/component.php:171
#14: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:594
#15: CBitrixComponent->__includeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:653
#16: CBitrixComponent->includeComponent(string, array, boolean)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1041
#17: CAllMain->IncludeComponent(string, string, array, boolean)
	/home/bitrix/www/catalog/index.php:2492
#18: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#19: include_once(string)
	/home/bitrix/www/bitrix/urlrewrite.php:5

Fatal error: Uncaught Bitrix\Main\DB\SqlQueryException: Mysql query error: (2006) MySQL server has gone away in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:137 Stack trace: #0 /home/bitrix/www/bitrix/modules/main/lib/db/mysqlcommonconnection.php(132): Bitrix\Main\DB\MysqliConnection->queryInternal('SELECT * FROM `...') #1 /home/bitrix/www/bitrix/modules/main/lib/db/connection.php(716): Bitrix\Main\DB\MysqlCommonConnection->getTableFields('b_sec_session') #2 /home/bitrix/www/bitrix/modules/main/lib/db/sqlhelper.php(387): Bitrix\Main\DB\Connection->getTableField('b_sec_session', 'SESSION_ID') #3 /home/bitrix/www/bitrix/modules/main/lib/entity/datamanager.php(974): Bitrix\Main\DB\SqlHelper->prepareAssignment('b_sec_session', 'SESSION_ID', 'rpJ90OEQTrzW1e3...') #4 /home/bitrix/www/bitrix/modules/security/classes/general/session_db.php(92): Bitrix\Main\Entity\DataManager::delete(Array) #5 [internal function]: CSecuritySessionDB::write('rpJ90OEQTrzW1e3...', 'SESS_AUTH|a:1:{...') #6 [internal function]: sess in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 137