We had this same issue with our installation. The problem is in bp_core_avatar_upload_path and bp_core_avatar_url functions located in bp-core/bp-core-avatars.php.
For bp_core_avatar_upload_path I changed this line:
` $upload_dir = WP_CONTENT_DIR . ‘/blogs.dir/’ . BP_ROOT_BLOG . ‘/files/’;`
to:
`$upload_dir = WP_CONTENT_DIR . ‘/uploads’;`
For bp_core_avatar_url I changed this line:
`$upload_dir = str_replace( get_blog_option( $current_blog->blog_id, ‘home’ ) , get_blog_option( BP_ROOT_BLOG, ‘home’ ), $upload_dir );`
to:
`$upload_dir = get_blog_option( BP_ROOT_BLOG, ‘home’ ) . ‘/wp-content/uploads/’;`
This is probably not the best way to fix this but it works.
