I looked through the src, it seems your problem is with FOSUserBundle or the Symfony's own SecurityBundle that ships with Symfony2 (not to be confused with CCDNUserSecurityBundle, as they do different things).
If you do a service dump in the console, you can see that that service is referenced from the following bundle: Symfony\Bundle\SecurityBundle, references to which can be found in these files:
My advice is the go into the app/AppKernel, and disable CCDNUserSecurityBundle by commenting the line out, and doing the same in app/config.yml for CCDNUserSecurityBundle's configuration and resolving the issue with your setup regarding Symfony's own SecurityBundle first. Once you have corrected the issue then go and uncomment CCDNUserSecurityBundle, and hopefully it should be working then.
My advice is to go through the setup documentation for Symfony sandbox again and then FOSUserBundle again while CCDNUserSecurityBundle is temporarily disabled as i don't believe this is related and this should hopefully point you in the right direction.
Best of luck, and let me know how it goes. :)