Whose Error Is It?
Java printed this
java.lang.UnsupportedClassVersionError: has been compiled by a more recent version of the Java Runtime
What it meansThe class files were built with a newer JDK than the Java runtime you are using to run them, so the JVM cannot load them.
The first thing to checkCompare java -version with the JDK used for the build; either run on the newer runtime or compile with --release set to your runtime's version.