B4J Question B4JPackager11 builds on Ubuntu but cannot run it

So I finally got my Ubuntu linux machine to successfully run B4JPackager11 and build the folders and files. I see the same run.command that I saw when I did this on my Mac. However, when I double click on the run.command file, the busy icon appears for about 10 seconds and then goes back to the normal cursor icon...and in the mean time, nothing happens on the screen. So my jar file doesn't run. I read about editing the run.command file and changing it's property settings but I don't see anything about running as a jar file.

Thanks for any help.