Can't Enable Membership w/ Main Site Set in Wp-config

I've been having this issue for over a month now, and it's really starting to throw a monkey wrench in my setup.

Whenever I try to set the main site for Membership in wp-config, it will not allow me to enable the plugin. I really need to get this working sooner, rather than later.

I've been getting no support from Eugene on this. Is he still the lead developer for Membership?