Based on the forum post, The following EJB cannot be injected into clients:

@DAO
@Local(ResultDAOBean.class)
@Stateless
public ResultDAO extends AbstractDAO<Result> implements ResultDAOBean

Happens the same with/without @Local

The problem comes in when AbstractDAO implements something (e.g. AbstractDAOBean<E>) or ResultDAOBean extends an interfacet (e.g.AbstractDAOBean<E>). The interface AbstractDAOBean isn't marked as an EJB itnerface, and only one of these two would implement/extend it (ideally, ResultDAOBean).

The injection point results in the following exception:

Caused by: java.lang.IllegalStateException: Unable to convert ejbRef for ejb ResultDAO to a business object of type interface AbstractDAOBean
at com.sun.ejb.containers.EjbContainerServicesImpl.getBusinessObject(EjbContainerServicesImpl.java:104)
at org.glassfish.weld.ejb.SessionObjectReferenceImpl.getBusinessObject(SessionObjectReferenceImpl.java:60)
at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:121)
at jpa.dao.EvaluationDAOBean_$$javassist_110.getEM(EvaluationDAOBean$$_javassist_110.java)
at NewSessionBean.init(NewSessionBean.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.ejb.containers.interceptors.BeanCallbackInterceptor.intercept(InterceptorManager.java:1006)
at com.sun.ejb.containers.interceptors.CallbackChainImpl.invokeNext(CallbackChainImpl.java:61)
at com.sun.ejb.containers.interceptors.CallbackInvocationContext.proceed(CallbackInvocationContext.java:109)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCallback(SystemInterceptorProxy.java:133)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.init(SystemInterceptorProxy.java:115)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.ejb.containers.interceptors.CallbackInterceptor.intercept(InterceptorManager.java:961)
at com.sun.ejb.containers.interceptors.CallbackChainImpl.invokeNext(CallbackChainImpl.java:61)
at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:390)
at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:373)
at com.sun.ejb.containers.AbstractSingletonContainer.createSingletonEJB(AbstractSingletonContainer.java:518)
... 38 more