java.lang.UnsupportedClassVersionError: javassist/ClassPool : Unsupported major.minor version 52.0 -------------------------------------------------------------------------------------------------- Key: JASSIST-257 URL: https://issues.jboss.org/browse/JASSIST-257 Project: Javassist Issue Type: Release Environment: Linux Tomcat 7 / JDK 1.6.0.41 / RHEL 5 Javassist version 3.20.0-GA Reporter: Simon Franquet Assignee: Shigeru Chiba Sorry, not sure it's the right place to post this, but anyway : during instrumentation, class transformation fails with the this : Redefinition class failed ! java.lang.UnsupportedClassVersionError: javassist/ClassPool : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at com.meilleuregestion.instrumentation.Transformer.transform(Transformer.java:33) at sun.instrument.TransformerManager.transform(TransformerManager.java:169) at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:365) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2895) at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1173) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1681) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) at org.apache.catalina.util.Introspection.loadClass(Introspection.java:143) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:135)