[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SHOW TABLES LIKE 'b_iblock_49_index_val'
/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:138
#0: Bitrix\Main\DB\MysqliConnection->queryInternal(string, array, NULL)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:332
#1: Bitrix\Main\DB\Connection->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/db/mysqlcommonconnection.php:48
#2: Bitrix\Main\DB\MysqlCommonConnection->isTableExists(string)
	/home/bitrix/www/bitrix/modules/iblock/lib/propertyindex/dictionary.php:54
#3: Bitrix\Iblock\PropertyIndex\Dictionary->isExists()
	/home/bitrix/www/bitrix/modules/iblock/lib/propertyindex/facet.php:57
#4: Bitrix\Iblock\PropertyIndex\Facet->__construct(integer)
	/home/bitrix/www/bitrix/components/bitrix/catalog.smart.filter/class.php:119
#5: CBitrixCatalogSmartFilter->executeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:569
#6: CBitrixComponent->includeComponent(string, array, NULL)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1032
#7: CAllMain->IncludeComponent(string, string, array)
	/home/bitrix/ext_www/telhistory.l-tech.ru/eng/collection/sect_include_left.php:25
#8: include(string)
	/home/bitrix/www/bitrix/components/bitrix/main.include/templates/.default/template.php:17
#9: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:535
#10: CBitrixComponentTemplate->__IncludePHPTemplate(array, array, string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:618
#11: CBitrixComponentTemplate->IncludeTemplate(array)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:657
#12: CBitrixComponent->showComponentTemplate()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:605
#13: CBitrixComponent->includeComponentTemplate()
	/home/bitrix/www/bitrix/components/bitrix/main.include/component.php:280
#14: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:535
#15: CBitrixComponent->__includeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:578
#16: CBitrixComponent->includeComponent(string, array, boolean)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1032
#17: CAllMain->IncludeComponent(string, string, array, boolean)
	/home/bitrix/www/bitrix/templates/new_telhistory/header.php:357
#18: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_after.php:87
#19: require(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:11
#20: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#21: require(string)
	/home/bitrix/ext_www/telhistory.l-tech.ru/eng/collection/index.php:2
#22: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:154
#23: include_once(string)
	/home/bitrix/www/bitrix/urlrewrite.php:2