In order to support JDK 9 we are moving to version 2.3 of jaxb however we still have consumers of our software who are still using JDK 7. Some of classes in the jaxb 2.3 jars provided are compiled at a JDK 8 level which results in exceptions such as:
java.lang.UnsupportedClassVersionError: com/sun/istack/Pool : Unsupported major.minor version 52.0