Do you have an ejb-jar.xml file in your application? If not, then add an empty ejb-jar.xml like this one (to mark the application as a EJB3 app):
<?xml version="1.0" encoding="UTF-8"?>
<ejb-jar
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/ejb-jar_3_0.xsd"
version="3.0">
</ejb-jar>