I've been using the Spark/Scala kernel on Jupyter (I'm not sure which version/how to check since it's not listed in jupyter kernelspec list).
All of a sudden, it stopped working. Poking around a bit, I've found an error preventing the kernel from initiating:
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/typesafe/config/ConfigMergeable : Unsupported major.minor version 52.0
I've seen several threads trying to address this issue (1, 2, 3, 4), but I don't follow them at all / how to apply suggested solutions to my situation.
It appears there's some sort of version mismatch somewhere inside how the kernel's working, but I don't know how to figure out where the mismatch is / how to fix it. I've looked at the following, but don't see (or know how to diagnose, really) any inconsistency:
printenv | grep "JAVA"
# JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
java -version
# java version "1.7.0_131"
# OpenJDK Runtime Environment (IcedTea 2.6.9) (7u131-2.6.9-0ubuntu0.14.04.2)
# OpenJDK 64-Bit Server VM (build 24.131-b00, mixed mode)
javac -version
# javac 1.7.0_131
This is being run on a remote machine, so I only have terminal access to diagnose / fix the problem.
