[Bitrix\Main\DB\ConnectionException] 
Mysql connect error [localhost]: (2006) MySQL server has gone away (400)
/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:65
#0: Bitrix\Main\DB\MysqliConnection->connectInternal()
	/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:122
#1: Bitrix\Main\DB\MysqliConnection->queryInternal(string, array, NULL)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:330
#2: Bitrix\Main\DB\Connection->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php:3193
#3: Bitrix\Main\ORM\Query\Query->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php:806
#4: Bitrix\Main\ORM\Query\Query->exec()
	/home/bitrix/www/bitrix/modules/main/lib/orm/data/datamanager.php:467
#5: Bitrix\Main\ORM\Data\DataManager::getList(array)
	/home/bitrix/www/bitrix/modules/catalog/general/catalog_sku.php:143
#6: CAllCatalogSku::GetInfoByProductIBlock(integer)
	/home/bitrix/www/bitrix/modules/iblock/lib/propertyindex/facet.php:45
#7: Bitrix\Iblock\PropertyIndex\Facet->__construct(integer)
	/home/bitrix/www/bitrix/modules/iblock/lib/propertyindex/querybuilder.php:28
#8: Bitrix\Iblock\PropertyIndex\QueryBuilder->__construct(integer)
	/home/bitrix/www/bitrix/modules/iblock/classes/general/iblockelement.php:657
#9: CAllIBlockElement->MkFilter(array, array, array)
	/home/bitrix/www/bitrix/modules/iblock/classes/general/iblockelement.php:3076
#10: 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:342
#11: CIBlockElement->prepareSql(array, array, boolean, array)
	/home/bitrix/www/bitrix/modules/iblock/classes/mysql/iblockelement.php:661
#12: CIBlockElement::GetList(array, array, boolean, boolean, array)
	/home/bitrix/www/local/php_interface/functions.php:4
#13: GetElementByFilter(array)
	/home/bitrix/www/local/php_interface/events.php:12
#14: SEORedirectProc()
	/home/bitrix/www/bitrix/modules/main/classes/general/module.php:475
#15: ExecuteModuleEventEx(array)
	/home/bitrix/www/bitrix/modules/main/include.php:285
#16: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_before.php:14
#17: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:10
#18: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#19: require(string)
	/home/bitrix/www/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