I have the following nginx configuration (at /etc/nginx/sites-available/default)
server { listen 80; ## listen for ipv4; this line is default and implied listen [::]:80 default ipv6only=on; ## listen for ipv6 root /usr/share/nginx/www; index index.php index.html index.htm; server_name _; location / { try_files $uri $uri/ /index.html; } error_page 404 /404.html; location ~ \.php$ { try_files $uri =404; fastcgi_split_path_info ^(.+\.php)(/.+)$; fastcgi_pass unix:/tmp/php5-fpm.sock; fastcgi_index index.php; include fastcgi_params; } location ~ /\.ht { deny all; } }  Instead of a 404 error, I'm getting 500 server errors on broken urls. How can I correct this?