[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SELECT 
	`security_session`.`SESSION_DATA` AS `SESSION_DATA`
FROM `b_sec_session` `security_session` 

WHERE `security_session`.`SESSION_ID` = 'aNeVJFpjQ21b685oFIlcWsqQKmuTW7mf'
LIMIT 0, 1

/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/main/lib/entity/datamanager.php:200
#5: Bitrix\Main\Entity\DataManager::getRow(array)
	/home/bitrix/www/bitrix/modules/security/classes/general/session_db.php:58
#6: CSecuritySessionDB::read(string)
	
#7: session_start()
	/home/bitrix/www/bitrix/modules/main/include.php:281
#8: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_before.php:14
#9: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:10
#10: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#11: require(string)
	/home/bitrix/www/product/index.php:2
#12: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#13: 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/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', 'aNeVJFpjQ21b685...') #4 /home/bitrix/www/bitrix/modules/security/classes/general/session_db.php(92): Bitrix\Main\Entity\DataManager::delete(Array) #5 [internal function]: CSecuritySessionDB::write('aNeVJFpjQ21b685...', '') #6 [internal function]: session_write_close() in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 137