I’ve a single WP installation with fastcgi cache.
I have configured it to use memcache as explained here. Everything was working fine and suddenly, when I load the site it gives me a blank white screen. I deactivated all plugins by renaming the plugins folder and activated the plugins one by one. Whenever I push the W3TC files to my plugins directory, it ends up in a blank white screen. And whenever I remove the w3tc directory from the plugins directory the site is up working fine.
Also there are three dropins in my wp-content directory
advanced-cache.php db.php object-cache.php
which are of w3tc plugin. Any suggestions on sorting this out?