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

				SELECT FROM_MODULE_ID, MESSAGE_ID, SORT, TO_MODULE_ID, TO_PATH,
					TO_CLASS, TO_METHOD, TO_METHOD_ARG, VERSION
				FROM b_module_to_module m2m
					INNER JOIN b_module m ON (m2m.TO_MODULE_ID = m.ID)
				ORDER BY 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/lib/eventmanager.php:230
#2: Bitrix\Main\EventManager->loadEventHandlers()
	/home/bitrix/www/bitrix/modules/main/lib/eventmanager.php:333
#3: Bitrix\Main\EventManager->findEventHandlers(string, string)
	/home/bitrix/www/bitrix/modules/main/classes/general/module.php:340
#4: GetModuleEvents(string, string, boolean)
	/home/bitrix/www/bitrix/modules/main/include.php:290
#5: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_before.php:14
#6: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:10
#7: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#8: require(string)
	/home/bitrix/www/ws_catalog/index.php:2
#9: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#10: 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/connection.php(330): Bitrix\Main\DB\MysqliConnection->queryInternal('\n\t\t\t\tSELECT FRO...', Array, NULL) #1 /home/bitrix/www/bitrix/modules/main/lib/eventmanager.php(230): Bitrix\Main\DB\Connection->query('\n\t\t\t\tSELECT FRO...') #2 /home/bitrix/www/bitrix/modules/main/lib/eventmanager.php(333): Bitrix\Main\EventManager->loadEventHandlers() #3 /home/bitrix/www/checkaccess/check.php(24): Bitrix\Main\EventManager->findEventHandlers('main', 'OnBeforeProlog') #4 [internal function]: CheckAccess->{closure}() #5 {main} thrown in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 137