If a persistence unit is deployed outside the EAR and if a bean within the EAR tries to inject the persistence unit, the injection fails because it can't find the persistence unit. Although the EJB3 spec does not allow such injection, JBoss did allow this (and still allows in the community 4.2.3 version). This JBoss specific feature no longer works and the regression is a side effect of JBPAPP-604.