iTop and NGINX
If you are running iTop on NGINX and choosed the enhanced portal, you are most likely to encounter a 404 error on some portal pages.
By default when accessing an url like : http://localhost/dir/script.php/arg1/arg2 NGINX thinks that script.php is a directory and tries to execute the index file located at /dir/script.php/arg1/arg2 (which doesn't exists).
In iTop this means that when NGINX is trying to execute http://localhost/pages/exec.php/browse/faq?exec_module=itop-portal.php&exec_page=index.php NGINX actually tries to execute /pages/exec.php/browse/faq which is not a real script.
You need to configure your NGINX server properly so it can serve those urls correctly.
The enhanced portal is based on the silex framework which provides a documentation about this configuration. You can adapt it to your instance. Just keep in mind that the portal uses /pages/exec.php instead of /index.php.
location / { try_files $uri $uri/ =404; } location ~ ^(.+.\.php)(/|$) { fastcgi_pass unix:/var/run/php5-fpm.sock; #For Debian, depends on distributive fastcgi_split_path_info ^(.+\.php)(/.*)$; include fastcgi_params; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; }