Slug gives 404 Error with NGINX

Hello,

when I try and open the slug I get a 404 Error. This is what's in the logs:

FastCGI sent in stderr: "PHP message: PHP Warning:  Missing argument 2 for QA_Core::wp_title() in /var/www/clients/client1/web6/web/p/qa/core/core.php on line 607
PHP message: PHP Warning:  Missing argument 3 for QA_Core::wp_title() in /var/www/clients/client1/web6/web/p/qa/core/core.php on line 607" while reading response header from upstream, client: 117.87.239.53, server: mirkogrewing.it, request: "GET / HTTP/1.1", upstream: "fastcgi://unix:/var/lib/php5-fpm/web6.sock:", host: "www.mirkogrewing.it"