Error running OPE with Java 18

[Ashleyishop]

When I upgrade to Oxygen Publishing Engine 26, I receive the following problem in my Jenkins console:

java.lang.UnsupportedClassVersionError: org/dita/dost/invoker/MainWithCPWildcardExpansion was compiled by a more current version of the Java Runtime (class file version 61.0); this version of the Java Runtime only recognizes class file versions up to 52.0.

Right now, I'm using Java 18, which should be fine, according to your required documentation:

java -version openjdk version "1.8.0_282" OpenJDK Runtime Environment (build 1.8.0_282-b08).
OpenJDK 64-Bit Server VM (build 25.282-b08, Mixed Mode)

Any idea what's going on?

I've also tried getting OPE to use JDK 21 instead, but I'm not sure whether I'm doing it correctly. That JDK is located in /opt/OpenJDK_21.0.1/bin, and I attempted to set the ENV environment variable in my Jenkins script, as well as JAVA_HOME, without success. Any views on this?

Thanks.

[julien_lacour]

Hello,

From your post I'm not sure if you are using Java 18 ("I'm using Java 18") or 1.8 (openjdk version "1.8.0_282").
Oxygen Publishing Engine 26.0 requires Java 17 or later as indicated in our user guide.
If you use another version, after setting JAVA_HOME, you need to use it in PATH so java -version shows the newer version.

Regards,
Julien