RELEASETHEBIRDS

Whenever I launch B-Team, the launcher does its thing, and the Mojang loading screen appears. It stays there for a while, but then the minecraft window closes and the launcher immediately reopens. I've tried logging out and back in, restarting my computer, etc. Anyone know the solution? (Side note: I'm not sure if I need the logs or not, but the file is too large. If you need the logs, let me know, and I'll make an edit.)