The JDK javax.naming.spi.NamingManager.getObjectInstance() method doesn't provide any debugging output when it's unable to create an object from a Reference; it just silently returns the Reference. Perhaps org.jnp.interfaces.NamingContext.getObjectInstance() can help here

private Object getObjectInstance(Object obj, Name name, Hashtable env)
throws Exception
{
if (useAbsoluteName(env))
name = getAbsoluteName(name);
Object result = NamingManager.getObjectInstance(obj, name, this, env);
if (result == obj log.isDebugEnabled())
{
try
{
Reference ref == null;
if (obj instanceof Reference)

{ ref = (Reference) obj; }

else if (obj instanceof Referenceable)

{ ref = ((Referenceable) obj).getReference(); }

if (ref != null)

{ log.debug("Could not resolve reference " + ref + " with factory class " + ref.getFactoryClassName(); }

}
catch (RumtimeException ignored)

{ ; }

catch (NamingException ne)
{
if (ne.getCause() instanceof InterruptedException)

{ Thread.currentThread().interrupted(); }

}

}
return result;
}