[Bitrix\Main\DB\SqlQueryException] 
Mysql query error: (2006) MySQL server has gone away (400)
SELECT ID FROM b_module ORDER BY ID
/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/modulemanager.php:20
#2: Bitrix\Main\ModuleManager::getInstalledModules()
	/home/bitrix/www/bitrix/modules/main/lib/loader.php:91
#3: Bitrix\Main\Loader::includeModule(string)
	/home/bitrix/www/bitrix/modules/main/classes/general/module.php:261
#4: CModule::IncludeModule(string)
	/home/bitrix/www/local/php_interface/init.php:57
#5: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include.php:241
#6: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog_before.php:14
#7: require_once(string)
	/home/bitrix/www/bitrix/modules/main/include/prolog.php:10
#8: require_once(string)
	/home/bitrix/www/bitrix/header.php:1
#9: require(string)
	/home/bitrix/www/ws_catalog/index.php:2
#10: include_once(string)
	/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#11: 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