[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
				
/var/www/html/bitrix/modules/main/lib/db/mysqliconnection.php:137
#0: Bitrix\Main\DB\MysqliConnection->queryInternal(string, array, NULL)
	/var/www/html/bitrix/modules/main/lib/db/connection.php:329
#1: Bitrix\Main\DB\Connection->query(string)
	/var/www/html/bitrix/modules/main/classes/general/main.php:4603
#2: CAllSite::GetCurTemplate()
	/var/www/html/bitrix/modules/main/include.php:542
#3: require_once(string)
	/var/www/html/bitrix/modules/main/include/prolog_before.php:14
#4: require_once(string)
	/var/www/html/bitrix/click.php:3