JRE version required unclear

[Adambean]

Hello,

As of version 1.4.0 I get this error on launch:

com/wurmly/mapviewer/App has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

I've got JRE version 1.8.0_301 installed, which is the latest mainstream available from Oracle right now. Is there some JRE preview version I should be using?

[Adambean]

Never mind, looks like Java 11 is now required, not 8:
https://newbedev.com/java-java-runtime-class-file-version-55-0-this-version-of-the-java-runtime-only-recognizes-class-file-versions-up-to-52-0-code-example

JRE for mainstream use only goes up to 8, so a later version from a JDK package must now be installed from here:
https://www.oracle.com/java/technologies/javase-downloads.html