$ ./AsciidocFX
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.xnio.nio.NioXnio$2 (file:/home/dgooding/AsciidocFX/lib/xnio-nio-3.3.8.Final.jar) to constructor sun.nio.ch.EPollSelectorProvider()
WARNING: Please consider reporting this to the maintainers of org.xnio.nio.NioXnio$2
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Ubuntu Desktop 16.04.5