BuddyPress.org

I’m almost certain you are getting a white page because, by copying parent theme functions.php into your child theme, you are re-declaring a function of the same name which PHP doesn’t like.

AFAIK you don’t need to copy the functions.php into your child, that should be inherited. If you are trying to change a function which has been written into parent functions.php, you’ll need to approach it another way.