org.osgi.framework.BundleException: Activator start error.
        at org.apache.felix.framework.Felix._startBundle(Felix.java:1579)
        at org.apache.felix.framework.Felix.startBundle(Felix.java:1469)
        at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1064)
        at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:258)
        at java.lang.Thread.run(Thread.java:613)
Caused by: java.lang.NoClassDefFoundError
        at org.codehaus.plexus.component.configurator.converters.special.ClassRealmConverter.class$(ClassRealmConverter.java:21)
        at org.codehaus.plexus.component.configurator.converters.special.ClassRealmConverter.canConvert(ClassRealmConverter.java:45)
        at org.codehaus.plexus.component.configurator.converters.lookup.DefaultConverterLookup.findConverterForType(DefaultConverterLookup.java:115)
        at org.codehaus.plexus.component.configurator.converters.lookup.DefaultConverterLookup.lookupConverterForType(DefaultConverterLookup.java:92)
        at org.codehaus.plexus.component.configurator.converters.ComponentValueSetter.initField(ComponentValueSetter.java:126)
        at org.codehaus.plexus.component.configurator.converters.ComponentValueSetter.<init>(ComponentValueSetter.java:77)
        at org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter.processConfiguration(ObjectWithFieldsConverter.java:131)
        at org.codehaus.plexus.component.configurator.BasicComponentConfigurator.configureComponent(BasicComponentConfigurator.java:56)
        at org.codehaus.plexus.component.configurator.AbstractComponentConfigurator.configureComponent(AbstractComponentConfigurator.java:61)
        at org.codehaus.plexus.component.configurator.AbstractComponentConfigurator.configureComponent(AbstractComponentConfigurator.java:52)
        at org.codehaus.plexus.DefaultPlexusContainer.initializePhases(DefaultPlexusContainer.java:869)
        at org.codehaus.plexus.DefaultPlexusContainer.initialize(DefaultPlexusContainer.java:826)
        at org.codehaus.plexus.DefaultPlexusContainer.construct(DefaultPlexusContainer.java:416)
        at org.codehaus.plexus.DefaultPlexusContainer.<init>(DefaultPlexusContainer.java:209)
        at org.apache.geronimo.gshell.osgi.GShell.<init>(GShell.java:89)
        at org.apache.geronimo.gshell.osgi.Activator.start(Activator.java:23)
        at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589)
        at org.apache.felix.framework.Felix._startBundle(Felix.java:1535)
        ... 4 more