Game can't launch since S2 update

Ever since Nightfall launched, my game can't launch past the signing-in screen. After saying "signing in", the screen will go black, eventually crashing to desktop. There have been a handful of times when it does miraculously get past this hurdle, and I'm allowed to play, but these instances are immensely rare. I know that the game isn't quite optimized for a gaming laptop, but it worked more-or-less fine in S1. I'm not too confident that a fix could be established, but since I've already tried most troubleshooting routes, I'd appreciate some more... Out of the box approaches if anyone has ideas.