[Bitrix\Main\DB\ConnectionException] 
Mysql connect error [localhost, 127.0.0.1] (400)
/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlconnection.php:50
#0: Bitrix\Main\DB\MysqlConnection->connectInternal()
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlconnection.php:103
#1: Bitrix\Main\DB\MysqlConnection->queryInternal(string, array, NULL)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/connection.php:329
#2: Bitrix\Main\DB\Connection->query(string, NULL)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/connection.php:378
#3: Bitrix\Main\DB\Connection->queryExecute(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/php_interface/after_connect_d7.php:3
#4: include(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/connection.php:920
#5: Bitrix\Main\DB\Connection->afterConnected()
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlconnection.php:64
#6: Bitrix\Main\DB\MysqlConnection->connectInternal()
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlconnection.php:103
#7: Bitrix\Main\DB\MysqlConnection->queryInternal(string, NULL, NULL)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/connection.php:329
#8: Bitrix\Main\DB\Connection->query(string, NULL, integer, integer)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/connection.php:357
#9: Bitrix\Main\DB\Connection->queryScalar(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/security/lib/session.php:115
#10: Bitrix\Security\SessionTable::lock(string, integer)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/security/classes/general/session_db.php:52
#11: CSecuritySessionDB::read(string)
	
#12: session_start()
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/include.php:301
#13: require_once(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/include/prolog_before.php:14
#14: require_once(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/include/prolog.php:10
#15: require_once(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/header.php:1
#16: require(string)
	/home/bitrix/ext_www/labstand.ru/catalog/index.php:2
#17: include_once(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/modules/main/include/urlrewrite.php:159
#18: include_once(string)
	/home/bitrix/ext_www/labstand.ru/bitrix/urlrewrite.php:2

Fatal error: Uncaught exception 'Bitrix\Main\DB\SqlQueryException' with message 'Mysql query error: MySQL server has gone away' in /home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlconnection.php:116 Stack trace: #0 /home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlcommonconnection.php(132): Bitrix\Main\DB\MysqlConnection->queryInternal('SELECT * FROM `...') #1 /home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/connection.php(715): Bitrix\Main\DB\MysqlCommonConnection->getTableFields('b_sec_session') #2 /home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/sqlhelper.php(387): Bitrix\Main\DB\Connection->getTableField('b_sec_session', 'SESSION_ID') #3 /home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/entity/datamanager.php(830): Bitrix\Main\DB\SqlHelper->prepareAssignment('b_sec_session', 'SESSION_ID', '633nb1XTJoiR9qn...') #4 /home/bitrix/ext_www/labstand.ru/bitrix/modules/security/classes/general/session_db.php(92): Bitrix\Main\Entity\DataManager::delete('633nb1XTJoiR9qn in /home/bitrix/ext_www/labstand.ru/bitrix/modules/main/lib/db/mysqlconnection.php on line 116