hi viktor i face the following who lead to 403 error 500 on the server during 5 min
[Sun May 29 00:22:16 2016] [error] [client 78.46.50.246] FastCGI: server "/home/clients/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/.config/apache/crashdebug.fr/.fpm/php5.external" stderr: PHP message: PHP Notice: Undefined index: robots in /home/clients/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/web/plugins/system/easyfrontendseo/easyfrontendseo.php on line 391