BuddyPress.org

deactivate the buddypress and then network activate it, make sure you followed all those steps given in readme came with buddypress @Chris O’Brien you have disabled the registration and there seems to be no way to contact you try ND’s solution if you are using si captcha “”Found the cullprit; the ‘SI Captcha’ plugin was preventing it because of a wrong set file permission.
Check the plugin settings page and it will say what is wrong””
there was this problem with the last version of buddypress i don’t think this still exists someone if you still face it do tell wp ver buddypress ver and if possible your site address