This is easy to see with the Populated Enterprise
Application or the EJB Module project.
1. create one of these projects.
2. deploy. The deploy will fail.
The app is not initially deployable. The error is
not detected until the app is handed to the server.
The root cause of this is the same as the root cause of 49490:
The DD is not valid [in this case there isn't an ejb "subelement" of
the enterprise-beans element of the dtd/schema.
validating the XML earlier in the build process would catch this issue.
*** This issue has been marked as a duplicate of 49490 ***