You can delete black-listed items by selecting it and press delete (or <- key).
Then try to re-scan... still crashing?
Just tried here successfully (version 1.56.30 of AD in AU, and V1 of AD in VST). So if you still can't use AD in AU mode, the truth is elsewhere... Maybe reboot and try again?
Oh well, I didn't try the delete key since you can't delete items in the layout tree with it... lol And the black-listed plug-in didn't have a contextual menu.
But that did the trick! It's back again and now I can post a screenshot with a green plug-in window. See the white plug-in window thread...