The correct version of the JAR shows up Java Dependencies Pane but when executed a different version is added to the -cp arguments. Environment Operating System: OSX JDK version: 1.8.0_201 Visual ...

alternatively, you can add the api jar in its entirety to the classpath when running the jar. The api jar can be found at xyz.wagyourtail.jvmdowngrader:jvmdowngrader-java-api:0.9.0:downgraded-8 there ...

Just add something like:<BR>Class-Path: images<BR>to the MANIFEST.MF and put it back into the jar.<BR>Now when you run it using java -jar myprogram.jar the classpath will contain myprogram.jar and ...