Vassal 3.4.11 Does not start (nothing happens)

Intel Core i7 64 bit 5500U 2.40Ghz Cache 4MB
NVidia GeForce 610M
Ubuntu 20.04.1 LTS Release 20.04
OpenJDK Version 2020-11-04

I have downloaded Vassal 3.4.11
When I tap on nothing happens
(No error messages)

Thank you
Angelo (Verona Italy)

What happens when you try running from a terminal instead?

(Note also that 3.4.12 is current now.)