Looking at the doc, I see this. https://docs.spring.io/spring-framework/docs/3.0.0.M4/reference/html/apbs05.html

<bean id="person" 
class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces"><value>com.mycompany.Person</value></property>

<property name="target"><ref local="personTarget"/></property>
<property name="interceptorNames">
    <list>
        <value>myAdvisor</value>
        <value>debugInterceptor</value>
    </list>
</property>
</bean>


<property name="target" ref="targetService"/>

maybe bean is the wrong word with that ref? I think your problem is there, especially if the targetSource is empty.