To reproduce this, you need to apply the patch for JDK-8150130 to a recent jdk9-dev and then use that JDK to build the JavaFX docs as described in JDK-8150130.

We get the following exception:

javadoc: error - jdk.javadoc.internal.doclets.toolkit.util.DocletAbortException: jdk.javadoc.internal.doclets.toolkit.util.DocletAbortException: jdk.javadoc.internal.doclets.toolkit.util.DocletAbortException: com.sun.tools.javac.code.ClassFinder$BadClassFile: bad class file: /localhome/kcr/javafx/9-kcr/jfx/rt/modules/web/build/classes/main/javafx/scene/web/HTMLEditorSkin$2.class
  bad enclosing method attribute for class javafx.scene.web.HTMLEditorSkin$2
  Please remove or make sure it appears in the correct subdirectory of the classpath.