Prevent empty multirating to be computed in average
"Enable Optional Multirating" option must be on
add_filter( 'geodir_reviewrating_comment_rating_fields', 'gdsnippet_skip_optional_ratings', 99, 0 );
functiongdsnippet_skip_optional_ratings() {
return (bool) geodir_get_option( 'rr_optional_multirating' );
}