I wrote a small Java desktop application using NetBeans, Java 8 and JavaFX 8 on my macBook under High Sierra.  I can launch it in terminal manually by using a bash script but double clicking on the Jar in finder fails (right clicking and selecting open fails, too)and I receive a suggestion that I look for errors in Console, whatever that is, but get no other clue as to what's failing.  It's a very specialized app that I'll probably only distribute to a couple of co-workers who don't work in terminal.

Google has given me solutions that are out of date, the Oracle solution (out of date) provided a link that proved useless.

What do I need to do to be able make the Jar file executable from Finder? How can I get more information on what's wrong? Since it's not signed it might be that Gatekeeper is the culprit.