nginx showing blank PHP pages

Also had this issue and finally found the solution here. In short, you need to add the following line to your nginx fastcgi config file (/etc/nginx/fastcgi_params in Ubuntu 12.04)

fastcgi_param PATH_TRANSLATED $document_root$fastcgi_script_name;

For reference, I am attaching my location block for catching files with the .php extension:

location ~ \.php$ {
    include /path/to/fastcgi_params;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
}

Double-check the /path/to/fastcgi_params, and make sure that it is present and readable by the nginx user.

replace

include fastcgi_params;

with

include fastcgi.conf;

and remove fastcgi_param SCRIPT_FILENAME ... in nginx.conf

Many users fall in this thread expecting to find a solution for blank pages being displayed while using nginx+php-fpm, me being one of them. This is a recap of what I ended up doing after reading many of the answers here plus my own investigations (updated to php7.2):

1) Open /etc/php/7.2/fpm/pool.d/www.conf and check the value of parameter listen.

listen = /var/run/php/php7.2-fpm.sock

2) Parameter listen should match fastcgi_pass parameter in your site configuration file (i,e: /etc/nginx/sites-enabled/default).

fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;

3) Check the file actually exists:

$ file /var/run/php/php7.2-fpm.sock 
/var/run/php/php7.2-fpm.sock: socket

4) If it doesn't exist that means php7.2-fpm is not running, so you need to restart it:

$ sudo /etc/init.d/php7.2-fpm restart
[ ok ] Restarting php7.2-fpm (via systemctl): php7.2-fpm.service.

With regard to the location section in /etc/nginx/sites-enabled/default:

   # pass PHP scripts to FastCGI server
   #
   location ~ \.php$ {
      include snippets/fastcgi-php.conf;

      # With php-fpm (or other unix sockets):
      fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
   }

Check the file snippets/fastcgi-php.conf exists at location /etc/nginx/:

$ file /etc/nginx/snippets/fastcgi-php.conf
/etc/nginx/snippets/fastcgi-php.conf: ASCII text

This file contains a list of variable definitions required by php7.2-fpm. The variables are defined directly or through an include of a separated file.

 include fastcgi.conf;

This file is located at /etc/nginx/fastcgi.conf and it looks like:

fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
...
fastcgi_param  REDIRECT_STATUS    200;

nginx includes two possible parameter files: fastcgi_params and fastcgi.conf. The difference between both is the definition of variable SCRIPT_FILENAME:

$ diff fastcgi_params fastcgi.conf 
1a2
> fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;

To make a long story short, fastcgi.conf should always work. If for some reason you're set up is using fastcgi_params, you should define SCRIPT_FILENAME:

location ~ \.php$ {
  include snippets/fastcgi-php.conf;

  # With php-fpm (or other unix sockets):
  fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;

  fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;
}

Now reload nginx configuration:

$ sudo nginx -s reload

And check a php file is displayed correctly. For instance:

/var/www/html/test.php

<pre><?php var_export($_SERVER)?></pre>

Where /var/www/html is the path to the document root.

If despite all that, you're still seeing a blank file, make sure your php.ini has short_open_tag enabled (if you're testing a PHP page with short tags).