deepthought:~/Downloads/pcgen$ java -jar pcgen.jar
14:46:48.279 INFO main Main:145 Starting PCGen v6.06.01
14:46:48.348 INFO main LanguageBundle:131 Initialising language bundle with locale en_GB.
14:46:48.557 SEVERE main Main:614 Uncaught error - ignoring
java.lang.reflect.InaccessibleObjectException: Unable to make member of class sun.awt.X11.XToolkit accessible:  module java.desktop does not export sun.awt.X11 to unnamed module @18be83e4
        at sun.reflect.Reflection.throwInaccessibleObjectException(java.base@9-internal/Reflection.java:420)
        at java.lang.reflect.AccessibleObject.checkCanSetAccessible(java.base@9-internal/AccessibleObject.java:174)
        at java.lang.reflect.Field.checkCanSetAccessible(java.base@9-internal/Field.java:170)
        at java.lang.reflect.Field.setAccessible(java.base@9-internal/Field.java:164)
        at pcgen.gui2.tools.Utility.setApplicationTitle(Utility.java:472)
        at pcgen.system.Main.configureUI(Main.java:411)
        at pcgen.system.Main.startupWithGUI(Main.java:367)
        at pcgen.system.Main.main(Main.java:159)