When the parent attribute of a J2EEDomain MBean is called a RuntimeMBeanException: null Cause: java.lang.NullPointerException is launched.

We can see this error in the JMX-Console in the MBean: jboss.management.local:name=Manager,j2eeType=J2EEDomain the field parent have a "RuntimeMBeanException" string instead a null or empty value.

twiddle.bat get "jboss.management.local:name=Manager,j2eeType=J2EEDomain" parent return a error too.

To FIX this problem replace the getparent() method implementation of org.jboss.management.j2ee.J2EEManagedObject class for this code.:

public String getparent()

{ return (parentName != null) ? parentName.getCanonicalName() : null; }