[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SET NAMES 'utf8'
/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, NULL)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:379
#2: Bitrix\Main\DB\Connection->queryExecute(string)
	/home/bitrix/www/bitrix/php_interface/after_connect_d7.php:7
#3: include(string)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:984
#4: Bitrix\Main\DB\Connection->afterConnected()
	/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:81
#5: Bitrix\Main\DB\MysqliConnection->connectInternal()
	/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:122
#6: Bitrix\Main\DB\MysqliConnection->queryInternal(string, NULL, NULL)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:330
#7: Bitrix\Main\DB\Connection->query(string, NULL, integer, integer)
	/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:358
#8: Bitrix\Main\DB\Connection->queryScalar(string)
	/home/bitrix/www/bitrix/modules/main/lib/composite/internals/locker.php:25
#9: Bitrix\Main\Composite\Internals\Locker::lock(string)
	/home/bitrix/www/bitrix/modules/main/lib/composite/engine.php:475
#10: Bitrix\Main\Composite\Engine::processPageContent(string)
	/home/bitrix/www/bitrix/modules/main/lib/composite/engine.php:422
#11: Bitrix\Main\Composite\Engine::endBuffering(string, string)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:3196
#12: CAllMain->EndBufferContent(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/main.php:3140
#13: CAllMain->EndBufferContentMan()
	/home/bitrix/www/bitrix/modules/main/include/epilog_after.php:36
#14: require(string)
	/home/bitrix/www/bitrix/modules/main/include/epilog.php:3
#15: require_once(string)
	/home/bitrix/www/bitrix/footer.php:4
#16: require(string)
	/home/bitrix/www/catalog/index.php:600
#17: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#18: 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', 'xjlBi30B04uF1ah...') #4 /home/bitrix/www/bitrix/modules/security/classes/general/session_db.php(92): Bitrix\Main\ORM\Data\DataManager::delete(Array) #5 [internal function]: CSecuritySessionDB::write('xjlBi30B04uF1ah...', 'SESS_AUTH|a:1:{...') #6 [internal function]: in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 137