Running the attached program outputs the following performance note text in the console:

2013-12-12 21:46:32.995 java[813:507] CoreText performance note: Client called CTFontCreateWithName() using name "Helvetica Bold" and got font with PostScript name "Helvetica-Bold". For best performance, only use PostScript names when calling this API.
2013-12-12 21:46:32.995 java[813:507] CoreText performance note: Set a breakpoint on CTFontLogSuboptimalRequest to debug.

Sample application:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.stage.Stage;

public class FontError extends Application {
    @Override public void start(Stage stage) {
        System.out.println("javafx.runtime.version=" + System.getProperty("javafx.runtime.version"));
        Label label = new Label("Font Error");
        label.setStyle("-fx-font: 14px \"Helvetica\";");
        Scene scene = new Scene(label);
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}