(keitai-l) Disappearing JAR file data

Greetings - my 1st posting - be gentle.

Trying to get DoJa-3.5 plugin working on Eclipse. I set the values in
the project setup, including AppSize at 8. I create a JAR file using
the JAR exporter.  However, when I try to run HelloWorld I get an
error saying Appsize(=0) must be more than 1.

When I check the project setup again and AppSize is set to 0. I set
that to 8 again and check eht JAM file and it says AppSize is 8. Try
to run HelloWorld again, but I get the same AppSize(=0) error. I
export another JAR file and confirm that its contents are correct
using the command jar tf HelloWorld.jar. It's all looking good, but
when I run it again I get the same  AppSize(=0) error. I do another
jar tf HelloWorld.jar and it shows that there is a HelloWorld.jar
file, but it's completely empty. But a check of the created time stamp
of the file shows that was created in the last minute.

So obviously eclipse is creating a new file with each run, but not
writing anything into the file.

What settings and/or preferences do I need to change to get eclipse to
write data into the JAR file? Is there a way to bypass the JAR file
creation when running HelloWorld? Becuase I can just manually create a
jar file in a command window.

Mark