The cssref.html has the following example, showing how to load internal resources from jfxrt.jar. As of jdk-9+111 there is no more jfxrt.jar and it is not legal to do this. This needs to be removed along fixing up any other related documentation that talks about loading internal resources.

 918 <!-- FIXME: this is no longer allowed and should be removed or redone -->
 919 <p>This snippet of code creates a scene filled with the "paste" image from HTMLEditor which is found in jfxrt.jar.</p>
 920 <textarea rows="9" cols="132">
 921
 922 @Override public void start(Stage stage) {
 923 StackPane root = new StackPane();
 924 root.setStyle("-fx-background-image: url(/com/sun/javafx/scene/control/skin/modena/HTMLEditor-Paste.png);");
 925 Scene scene = new Scene(root, 300, 250);
 926 stage.setScene(scene);
 927 stage.show();
 928 }
 929 </textarea>