GitHub

How am I supposed to use it?

Exception in thread "main" java.lang.UnsupportedClassVersionError: Launcher has been compiled by a more recent version of the Java Runtime (class file version 60.0), this version of the Java Runtime ...
GitHub

Improve error message when loading an invalid class version

java.lang.UnsupportedClassVersionError: some/Class has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file ...