An MBean with:

public void setObj(javax.management.ObjectName someObject)

<mbean ...>
<attribute name="Obj" />

causes "java.lang.ClassNotFoundException: javax.management.MalformedObjectNameException from [Module \"org.jboss.common-beans:main\"

org.jboss.common.beans.property.ObjectNameEditor in that module is used to convert to ObjectName objects, and requires MalformedObjectNameException but it is not on the classpath of that module.