[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SELECT 
	`catalog_group_access`.`CATALOG_GROUP_ID` AS `CATALOG_GROUP_ID`,
	`catalog_group_access`.`ID` AS `UALIAS_0`
FROM `b_catalog_group2group` `catalog_group_access` 

WHERE `catalog_group_access`.`GROUP_ID` = 2
AND `catalog_group_access`.`BUY` = 'Y'
ORDER BY `CATALOG_GROUP_ID` ASC
/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:3304
#2: Bitrix\Main\ORM\Query\Query->query(string)
	/home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php:816
#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/components/bitrix/catalog.element/class.php:124
#5: CatalogElementComponent->initAdditionalCacheKeys(array)
	/home/bitrix/www/bitrix/modules/iblock/lib/component/element.php:775
#6: Bitrix\Iblock\Component\Element->getCacheKeys()
	/home/bitrix/www/bitrix/modules/iblock/lib/component/base.php:3923
#7: Bitrix\Iblock\Component\Base->initResultCache()
	/home/bitrix/www/bitrix/modules/iblock/lib/component/base.php:4462
#8: Bitrix\Iblock\Component\Base->loadData()
	/home/bitrix/www/bitrix/modules/iblock/lib/component/base.php:4442
#9: Bitrix\Iblock\Component\Base->initialLoadAction()
	/home/bitrix/www/bitrix/modules/iblock/lib/component/element.php:271
#10: Bitrix\Iblock\Component\Element->initialLoadAction()
	
#11: call_user_func(array)
	/home/bitrix/www/bitrix/modules/iblock/lib/component/base.php:4627
#12: Bitrix\Iblock\Component\Base->doAction()
	/home/bitrix/www/bitrix/modules/iblock/lib/component/base.php:4645
#13: Bitrix\Iblock\Component\Base->executeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:648
#14: CBitrixComponent->includeComponent(string, array, object)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1039
#15: CAllMain->IncludeComponent(string, string, array, object)
	/home/bitrix/www/bitrix/templates/megamart_default/components/bitrix/catalog/catalog/element.php:358
#16: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:725
#17: CBitrixComponentTemplate->__IncludePHPTemplate(array, array, string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component_template.php:820
#18: CBitrixComponentTemplate->IncludeTemplate(array)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:745
#19: CBitrixComponent->showComponentTemplate()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:693
#20: CBitrixComponent->includeComponentTemplate(string)
	/home/bitrix/www/bitrix/components/bitrix/catalog/component.php:171
#21: include(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:604
#22: CBitrixComponent->__includeComponent()
	/home/bitrix/www/bitrix/modules/main/classes/general/component.php:663
#23: CBitrixComponent->includeComponent(string, array, boolean)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:1039
#24: CAllMain->IncludeComponent(string, string, array, boolean)
	/home/bitrix/www/catalog/index.php:1272
#25: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#26: include_once(string)
	/home/bitrix/www/bitrix/urlrewrite.php:2

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/connection.php(330): Bitrix\Main\DB\MysqliConnection->queryInternal('SELECT \n\t`main_...', Array, NULL) #1 /home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php(3304): Bitrix\Main\DB\Connection->query('SELECT \n\t`main_...') #2 /home/bitrix/www/bitrix/modules/main/lib/orm/query/query.php(816): Bitrix\Main\ORM\Query\Query->query('SELECT \n\t`main_...') #3 /home/bitrix/www/bitrix/modules/main/lib/orm/data/datamanager.php(500): Bitrix\Main\ORM\Query\Query->exec() #4 /home/bitrix/www/bitrix/modules/main/lib/analytics/sitespeed.php(95): Bitrix\Main\ORM\Data\DataManager::getList(Array) #5 /home/bitrix/www/bitrix/modules/main/lib/analytics/counter.php(92): Bitrix\Main\Analytics\SiteSpeed::isIntranetSite('s1') #6 /home/bitrix/www/bitrix/modules/main/classes/general/module.php(490): Bit in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 137