BuddyPress.org

First of all: https://buddypress.org/forums/topic/when-asking-for-support

Secondly: I am assuming you are using the default BP 1.1 theme for the moment – are you? If not, use the default theme until you have it all working. Make sure it is in /wp-content/themes/. Activate the theme in the normal way and select it; this warning message should go away.