Troubleshooting a Network site displaying a blank page [closed]

I have a WordPress install in Network mode, with subdomains.

sitex.example.com is displaying a white page, with nothing in the source code.

Other network sites display fine.

I renamed the theme the site was using, but it didn’t pick up Twenty Twelve in response.

A server response checker showed that the site is producing a 200 response code.

I went into Network Admin, and renamed sitex to sitey, but sitey.example.com produced a blank page also.

I checked .htaccess, and it contains the following code:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule . index.php [L]

I went into my hosting cPanel, and confirmed I still have my wildcard subdomain, and I don’t have a manual subdomain for sitex in cPanel.

I went back into Network Admin, and altered the settings of the site, and set Template & Stylesheet to twentytwelve, but this made no difference.

I’m lost.

I don’t know what else could be causing this.

Do you?

UPDATE

If I turn debugging on, I receive the following:

Warning: include(/…/wp-content/advanced-cache.php)
[function.include]: failed to open stream: No such file or directory
in /wp-settings.php on line 65

Warning: include() [function.include]: Failed opening
‘/…/wp-content/advanced-cache.php’ for inclusion
(include_path=”.:/usr/lib/php:/usr/local/lib/php”) in /wp-settings.php
on line 65

Notice: wpdb::escape is deprecated since version 3.6! Use
wpdb::prepare() or esc_sql() instead. in
/…/wp-includes/functions.php on line 2913

Warning: session_start() [function.session-start]: Cannot send session
cache limiter – headers already sent (output started at
/…/wp-settings.php:65) in
/…/wp-content/plugins/nivo-slider/nivo-slider.php
on line 10

The .htaccess does not have the information for caching so clear cache, network deactivate your caching plugin as well as the nivo slider plugin. If present, remove the setting for enabling caching in wp-config too.

Does /wp-admin.php load for that blog at this point?

If not, using phpmyadmin go into wp_blogid_options to see what is being loaded. You can clear those options and see if the blog loads.