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To see the error message, open a command prompt window, change to the directory with the jar file and enter the command:
java -jar THEJARFILENAMEHERE.jar

That does NOT look like the contents of an executable jar file.

I don't use an IDE to create my jar files so I can not help you. I use the jar command from a batch file.

Moved to IDE section.

Try opening the jar file in a zip utility to see if it has problems.