As of the latest update, vanished players are now doing damage to entites and other players. Tested with default settings, no vanish.damage permission.

 "Use OnEntityTakeDamage hook (Set to true to enable use of vanish.damage perm. Set to false for better performance)": false,

set this to true.

Got it, thanks. Like I said in the other thread, relaying this from a server I'm only an admin on, didn't know the config had been changed. Sorry about that.