If a .ear contains a application.xml as follows:

<application 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/application_6.xsd"
    version="6">
</application>

and also packages nested .sar files within the .ear, then those nested deployments are skipped. Removing the application.xml "fixes" the issue.

Since we allow .sar deployments to be picked up even in the absence of application.xml and since (JBoss specific) .sar deployments can't be mapped as a module in application.xml, it would be good to consider these nested .sar deployments, even in the presence of the application.xml.