The Facebook login problem has me quite annoyed since I don't see any improvement or anything similar, we have been almost 1 month since that error and there is no solution
We're right there with you. If you haven't already, please contact our customer service with your SGM Username and Facebook ID if you have it at www.skullgirlsmobile.com/contact
We are very slowly providing workarounds to get players back in the game, since we don't know how long Facebook will take. We're doing everything in our power to speed up the process.