HELP! Upfront freezes at 25% rendering.

Hello WPMUDEV,

I used Upfront to embed HTML for Twitter and Facebook feeds into the homepage.
However... now that I've done so, Upfront won't render past 25%.
I want to remove those feeds to fix things, but Upfront won't let me in!

I've already applied the following fixes to wp-config:
define('UPFRONT_DEBUG_LEVELS', 'dependencies');
define('WP_MEMORY_LIMIT', '256M');

Please respond ASAP - we have to launch tonight, and I don't know what to do... I've enabled remote access.

Thanks!