Using `jar` to create “zip” file … Mac won't open the zip, says “It is an unsupported format” … why?
I worked around my problem by installing 7-zip on Windows 10 and using that instead of jar like so ...
7z a c:\target\Application-1.5.zip .\Application-1.5\* -r 

Mac likes the zip file produced by 7-zip, so this will work for me.
But I'd still like to know how to make a zip file with jar that Mac's default unarchive can unzip.