[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SELECT 1 FROM b_messageservice_message WHERE SUCCESS_EXEC='N' AND (NEXT_EXEC < '2020-05-29 15:30:02' OR NEXT_EXEC IS NULL) LIMIT 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/messageservice/lib/queue.php:23
#2: Bitrix\MessageService\Queue::hasMessages()
	/home/bitrix/www/bitrix/modules/messageservice/lib/queue.php:43
#3: Bitrix\MessageService\Queue::run()
	/home/bitrix/www/bitrix/modules/main/classes/general/module.php:490
#4: ExecuteModuleEventEx(array)
	/home/bitrix/www/bitrix/modules/main/include/epilog_after.php:55
#5: require(string)
	/home/bitrix/www/bitrix/modules/main/include/epilog.php:3
#6: require_once(string)
	/home/bitrix/www/bitrix/footer.php:4
#7: require(string)
	/home/bitrix/www/catalog/index.php:593
#8: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#9: 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(140): Bitrix\Main\DB\MysqliConnection->queryInternal('SELECT * FROM `...') #1 /home/bitrix/www/bitrix/modules/main/lib/db/connection.php(779): Bitrix\Main\DB\MysqlCommonConnection->getTableFields('b_sec_session') #2 /home/bitrix/www/bitrix/modules/main/lib/db/sqlhelper.php(406): Bitrix\Main\DB\Connection->getTableField('b_sec_session', 'SESSION_ID') #3 /home/bitrix/www/bitrix/modules/main/lib/orm/data/datamanager.php(1619): Bitrix\Main\DB\SqlHelper->prepareAssignment('b_sec_session', 'SESSION_ID', 'u4PQ520BQb6AaeJ...') #4 /home/bitrix/www/bitrix/modules/security/classes/general/session_db.php(92): Bitrix\Main\ORM\Data\DataManager::delete(Array) #5 /home/bitrix/www/bitrix/modules/security/classes/general/session_handler.php(28): CSecuritySessionDB::write('u4PQ5 in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 137