I can not run jforum2.16 on IBM websphere6

[Migrated From Jforum.net]

visist http://locahost:9080/jforum
then i get the error message:






Error 500: java.lang.LinkageError: LinkageError while defining class: net.jforum.InstallServlet Could not be defined due to: net/jforum/InstallServlet (Unsupported major.minor version 49.0) This is often caused by having a class defined at multiple locations within the classloader hierarchy. Other potential causes include compiling against an older or newer version of the class that has an incompatible method signature. Dumping the current context classloader hierarchy: ==> indicates defining classloader ==>[0] com.ibm.ws.classloader.CompoundClassLoader@4946c499 Local ClassPath: C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\classes;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\activation.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\bsh-2.0b4.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\c3p0-0.9.0.2.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\commons-io-1.1.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\commons-logging.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\concurrent.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\dwr-1.1-RC1.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\freemarker-2.3.4.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\hsqldb-1.8.0.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\htmlparser-1.5.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\jcaptcha-all-1.0-RC2.0.1.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\jmxri.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\junit.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\log4j-1.2.12.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\mail.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\mysql-connector-java-3.1.12-bin.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\ojdbc14.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\postgresql-8.0-313.jdbc3.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\quartz-1.5.1.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\servlet-api.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\xalan.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\xercesImpl.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\xml-apis.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war\WEB-INF\lib\xom-1.0.jar;C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\installedApps\datatechNode01Cell\jforum_war.ear\jforum.war; Delegation Mode: PARENT_FIRST [1] com.ibm.ws.classloader.JarClassLoader@1227752601 Local Classpath: Delegation mode: PARENT_FIRST [2] com.ibm.ws.classloader.ProtectionClassLoader@4f5f8499 [3] com.ibm.ws.bootstrap.ExtClassLoader@7f46049b [4] sun.misc.Launcher$AppClassLoader@7f58449b [5] sun.misc.Launcher$ExtClassLoader@7f54449b ---Original exception--- java.lang.UnsupportedClassVersionError: net/jforum/InstallServlet (Unsupported major.minor version 49.0) at java.lang.ClassLoader.defineClass0(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java(Compiled Code)) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java(Compiled Code)) at com.ibm.ws.classloader.CompoundClassLoader._defineClass(CompoundClassLoader.java:576) at com.ibm.ws.classloader.CompoundClassLoader.findClass(CompoundClassLoader.java(Compiled Code)) at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java(Compiled Code)) at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled Code)) at java.beans.Beans.instantiate(Beans.java:202) at java.beans.Beans.instantiate(Beans.java:63) at com.ibm.ws.webcontainer.servlet.ServletWrapper$3.run(ServletWrapper.java:1384) at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java(Compiled Code)) at com.ibm.ws.webcontainer.servlet.ServletWrapper.loadServlet(ServletWrapper.java:1379) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:442) at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:2841) at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:220) at com.ibm.ws.webcontainer.VirtualHost.handleRequest(VirtualHost.java:204) at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:1681) at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:77) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:421) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:367) at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:94) at com.ibm.ws.tcp.channel.impl.WorkQueueManager.requestComplete(WorkQueueManager.java:54 at com.ibm.ws.tcp.channel.impl.WorkQueueManager.attemptIO(WorkQueueManager.java(Compiled Code)) at com.ibm.ws.tcp.channel.impl.WorkQueueManager.workerRun(WorkQueueManager.java:934) at com.ibm.ws.tcp.channel.impl.WorkQueueManager$Worker.run(WorkQueueManager.java:1021) at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java(Compiled Code)) --- end Original exception----
[originally posted on jforum.net by looyo]

[Migrated From Jforum.net]

How many forums are you going to post your problem in? This is at least your 3rd post for this ....

Have you tried searching for these types of errors on the IBM support site? There is a lot of good information there.
[originally posted on jforum.net by GatorBait3]

[Migrated From Jforum.net]

The problem comes from the jdk(the major/minor version):
IBM WAS uses a "personnal" version of jdk and i believe JForums classes are compiled with some recent jdk.
I've had this problem with IBM WebSphere more than once........
[originally posted on jforum.net by rayool]

[Migrated From Jforum.net]

Yeah, obviously: "Unsupported major.minor version 49.0)" always means your JRE is too old to run it. The fix is simple. Don't use a JVM from some earlier time in our nation's history.

Stick with the latest JVM. Java 5 has been out for three years now. There's no excuse to not run Java 5 these days. They shouldn't even be shipping older versions with anything anymore. Java 6 is right around the corner.

[originally posted on jforum.net by CaliforniaCCW]

[Migrated From Jforum.net]

The problem is that IBM uses its own jvm to compile jsp and run java applications . Therefore it's not your jvm that causes the problem but the one from IBM Websphere.
As an example if you develop a java using jdk 1.5, it wont work under Websphere even if you have the latestJVM on your computer.
The (awful) solution woulb be to recompile JForum classes using Websphere's Jdk........
[originally posted on jforum.net by rayool]