!!! Server error 500 when I enable the Ultimate Facebook plugin !!!

My website is ldccs.com (wordpress multisite)

When ever I enable the Ultimate Facebook Plugin then I get a Server Error. I contacted my host provider and they helped me narrow it down to this plugin being the cause of this.

"Server error
The website encountered an error while retrieving http://www.ldccs.com/. It may be down for maintenance or configured incorrectly."
(see the attached screen capture)

I have used this plugin once before on my kpcproductions.com website and it worked fine. I think this is happening because of something I did before enabling this plugin.

Before installing this plugin then one of the last things I did was remove/delete a plugin called Login Configurator. I am wondering if this Login Configurator plugin is effecting the Ultimate Facebook somehow.

As of right now the only plugins I have enabled are: Domain Mapping plugin, Blog Copier, Members Directory, Styles with Shortcodes for WordPress, Ultimate Branding, User Role Editor, WordPress Chat, WordPress Importer, WPMU DEV Dashboard and WPMU DEV Videos

Also my website has been redirecting people from the front page to the sign up page... (see the second screen capture attachment). I got a notice saying Greetings Site Administrator! You are currently allowing "all" registrations. To change or disable registration go to your Options page.

Right now I am having a hard time configuring the user logins to handle the way I want... What I want is for users to be able to register to a site on my network but not be redirected to the primary site (ldccs.com) is this possible. I am still somewhat new and have a lot to learn about Multisite.

For now I am going to try re-installing the Login Configurator plugin and checking the settings on the plugin to see if this does anything.