When i start BL, it shows console, loading common___, ETC.
But after the black screen when the menu pops up, it is instead all black and shows something about a Runtime Error.
Then, when i copied my entire Add-Ons folder to desktop(keeping the ones in the BL folder too), it stopped.
Badspot, i think this may be a glitch in v13. Please try to find the source and fix it.