Apache crashes and won't boot after a2ensite

I'm attempting to set up a node. I've been at this for a while. I've even followed the instructions to a tee several times now.

Everything works perfectly until I a2ensite the domain. I'm attempting to do a forums.domain.com configuration. Before I enable the domain, I can access the "It Works!" page via browser via the IP and forums.domain.tld.

After I enable it, Apache goes through the process then refuses to boot back up. Fail every time.

I'm getting damn frustrated.