The plugin gives the following strict errors:
Non-static method BpfbInstaller::check_paths() should not be called statically --- wp-content/plugins/buddypress-activity-plus/lib/class_bpfb_installer.php:34
Non-static method BpfbBinder::serve() should not be called statically --- wp-content/plugins/buddypress-activity-plus/bpfb.php:119
Non-static method BpfbCodec::register() should not be called statically, assuming $this from incompatible context --- wp-content/plugins/buddypress-activity-plus/lib/class_bpfb_binder.php:376
Please can you check into the cause and issue a fix for these?