Zettelkasten-3.2023.10.jar cannot be shut down

[bont007]

Hallo,
setup: Openjdk java 11 runtime, Linux Mint 21.2 "Victoria" Xfce Edition.
It seems that the above Zkn version cannot be shut down. I did not manage to open the packaged "old" version at all (Btw: what is "old" in this version?). I am possibly missing something obvious. As this is not recommended anyway I am reluctant to install Oracle JRE for this purpose only. Any hint is all the more appreciated.
Thomas

[RalfBarkow]

Only Java 1.8 is currently supported. "To build Zettelkasten, you need a Java Development Kit (JDK) 8 and Maven 3."