BuddyPress.org

Doesn’t really make sense that you haven’t even got to the activation stage of the plugin yet you say when you try and activate you get the error message, can you translate the error message literally verbatim as “site access” is not a usual error to throw up and when exactly does this occur, you have uploaded the BP folder to the plugins folder? then you are not able to access/loging to the WP backend? but you can if you remove the uploaded BP folder/files? None of this really makes a lot of sense and you best describe all the steps in as much detail as possible.