Main branch shouldn’t have updated, though steam downloaded ~20mb patch today (21/06/2016), after which BB gave me exact same behaviour.
Verifying Integrity of game cache fixed it for me.
Go to your Library -> rightclick BB -> Properties -> Local Files -> Verify.. – if you want to play ver.0.6.0.21, before UI update.
But later after switching to beta branch BB now crashes/refuses to load even before white screen could appear or write a log file.
When trying to manually install new VC2015, the lack of which seems to be the cause of this, installer says there was an unknown error, though it’s quite well known – for Windows 7 it requires service pack 1 to install properly and function.
So if you too have Win7 without SP1, my condolences..
