From JavaDoc of [DeltaSpikeConfig.java|https://github.com/apache/deltaspike/blob/master/de...] which is implemented by [JsfModuleConfig|https://github.com/apache/deltaspike/blob/master/deltaspi...]:

Validation error for subclasses of DeltaSpike JsfModuleConfig class ------------------------------------------------------------------- Key: JBIDE-17675 URL: https://issues.jboss.org/browse/JBIDE-17675 Project: Tools (JBoss Tools) Issue Type: Bug Components: cdi, cdi-extensions Affects Versions: 4.2.0.Beta3 Reporter: Alexey Kazakov Assignee: Alexey Kazakov Fix For: 4.2.0.Beta3 1. Clone deltaspike repo: {code}git clone https://git-wip-us.apache.org/repos/asf/deltaspike.git{code} 2. Import *deltaspike/examples* as an existing Maven project into JBT. 3. Open /deltaspike-jsf-playground/src/main/java/org/apache/deltaspike/playground/PlaygroundJsfModuleConfig.java with Java Editor 4. There is a validation error: *Managed bean class annotated @Specializes must directly extend the bean class of another managed bean [JSR-299 §3.1.4]* This error probably is a bug of CDI tools. We need to investigate it.