Can't get Artifact's jar file to work

Hello, I'm newbie if it's going about Kotlin. I've created succuessfuly project that I'm able to compile and run. Anyway I wanted to create jar file via IDEA's Artifiacts. Unfortunately I can't get it to work - i'm getting "Error: Could not find or load main class updatezipcreator.jar" while trying to run file via "java updatezipcreator.jar" command.

Here is my whole project:
https://bitbucket.org/pw321188/updatezipcreator/overview

To make jar runnable, you need to create META-INF/MANIFEST.MF file within your source directory with the following content:

Main-Class: my.runnable.Class