[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)

					SELECT
						`CONDITION`,
						TEMPLATE,
						SITE_ID
					FROM
						b_site_template
					ORDER BY
						SITE_ID,
						CASE
							WHEN IFNULL(LENGTH(`CONDITION`), 0)=0 THEN 2
							ELSE 1
						END,
						SORT
				
/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/classes/general/main.php:4542
#2: CAllSite::GetCurTemplate()
	/home/bitrix/www/bitrix/modules/main/include.php:534
#3: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_before.php:14
#4: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:10
#5: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#6: require(string)
	/home/bitrix/ext_www/s2/index.php:2
#7: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#8: include_once(string)
	/home/bitrix/www/bitrix/urlrewrite.php:2