# /usr/bin/java -jar apps/TLS-Server-Scanner.jar -connect www.bbc.co.uk:443
Exception in thread "main" java.lang.UnsupportedClassVersionError: de/rub/nds/tlsscanner/serverscanner/Main 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
Great. But what do I need to do to fix it?
#CrapErrorMessage
@tdp_org upgrade /usr/bin/java or recompile the .jar with an older javac/options
@falken Thanks 🙌🏻 - but my point is that the message doesn't tell me any of that. I installed java from java.com which i presume would be the latest version. Turns out not to be, or that maybe it's something different than that - JRE, JDK, Java - i don't really know what they do specifically. The ecosystem assumes *loads* of knowledge. I just find java super frustrating as a user, not saying anything else is perfect by any means but this is the worst IMO.
@falken That said, do you know how i'd upgrade `/usr/bin/java`? As I say, i downloaded it from java.com so i'd assume that'd be latest wouldn't it?
@tdp_org linux? there should be an openjdk package in your disto's list. Mac? dunno. Win? Get one from Chocolatey or similar.
Don't use Oracle's downloads. If they find you they'll set the lawyer's on you
