If I understand correctly, you are packaging Hibernate Validator into your WEB-INF/lib directory (at least that is what the screenshot suggests). This will cause conflicts with the Hibernate Validator version provided by the container itself. In your screenshot not all libraries have version information. So for example, there is no telling what version hibernate-validator.jar is. Are you not using a dependency management tool, eg Maven or Ivy? If not, I highly recommend to use one. In particular one can then change the scope of libraries which are provided by the container to 'provided'. This allows for easy development, but will make sure that no unnecessary jars make it into the final war file. Also, I wold cut out Eclipse. You want to re-produce it directly with the installed application server.