I'm having intermittent problems during initialization of an application deployed as a .sar. I'm getting the error mentioned in the subject line. When the error occurs it usually moves around - i.e,. the stack trace location and offending class changes from occurrence to occurrence. The context: 1. JBoss 4.0.3 SP1 | 2. There are several other applications deployed in the same JBoss instance - other .sars as well as an .ear that includes a .war. | 3. JMX is used by the .sar to start other internal services. | | | Attached below is a partial stack trace. Thanks in advance. | | Rich | | java.lang.IllegalStateException: ClassLoadingTask.loadedTask is null, name: javax.xml.rpc.handler.HandlerRegistry | | at org.jboss.mx.loading.RepositoryClassLoader.loadClassImpl(RepositoryClassLoader.java:516) | | at org.jboss.mx.loading.RepositoryClassLoader.loadClass(RepositoryClassLoader.java:377) | | at java.lang.ClassLoader.loadClass(Unknown Source) | | at java.lang.ClassLoader.loadClassInternal(Unknown Source) | | at example.MyClass.foo(MyClass.java:72) | | at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:150) | | at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644) | | at org.jboss.system.server.jmx.LazyMBeanServer.invoke(LazyMBeanServer.java:225) | | at com.avaya.ccr.jmx.JmxUtil.invoke(JmxUtil.java:69) | | at example.MyService.start(MyService.java:48) | | at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) | | at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) | | at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) | | at java.lang.reflect.Method.invoke(Unknown Source) | | at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:141) | | at org.jboss.mx.server.Invocation.dispatch(Invocation.java:80) | | at org.jboss.mx.server.Invocation.invoke(Invocation.java:72) | | at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:245) | | at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:644) | | at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) | | at java.util.concurrent.FutureTask.run(Unknown Source) | | at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source) | | at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) | | at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) | | at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) | | at java.lang.Thread.run(Unknown Source) | | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4010272#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...