The code block in Modena.java, line 104 - 138 should be removed. We may want to find why Modena needs to access JavaFX css resources and replace or eliminate those requirements. Otherwise this app will fail to work with JDK9:

Exception in thread "JavaFX Application Thread" java.lang.ExceptionInInitializerError
at java.lang.Class.forName0(java.base@9.0/Native Method)
at java.lang.Class.forName(java.base@9.0/Class.java:377)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplicationWithArgs$157(javafx.graphics@9.0/LauncherImpl.java:388)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(javafx.graphics@9.0/PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$174(javafx.graphics@9.0/PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(java.base@9.0/Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(javafx.graphics@9.0/PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(javafx.graphics@9.0/InvokeLaterDispatcher.java:95)
Caused by: java.lang.NullPointerException
at modena.Modena.<clinit>(Modena.java:107)
... 8 more
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(java.base@9.0/Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(java.base@9.0/NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9.0/DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(java.base@9.0/Method.java:502)
at sun.launcher.LauncherHelper$FXHelper.main(java.base@9.0/LauncherHelper.java:845)
Caused by: java.lang.NullPointerException
at sun.reflect.NativeMethodAccessorImpl.invoke0(java.base@9.0/Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(java.base@9.0/NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9.0/DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(java.base@9.0/Method.java:502)
at com.sun.javafx.util.ModuleHelper.getModule(javafx.graphics@9.0/ModuleHelper.java:77)
at com.sun.javafx.application.LauncherImpl.ensureReadable(javafx.graphics@9.0/LauncherImpl.java:69)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(javafx.graphics@9.0/LauncherImpl.java:417)
at com.sun.javafx.application.LauncherImpl.launchApplication(javafx.graphics@9.0/LauncherImpl.java:364)
... 5 more