Since I do use JBoss Tool I assume that this is cause by an error in the underlying seam generate-ui. It fails if you have entities annotated like this:

public class User implements Serializable

{ @Id @GeneratedValue private Long id; @OneToOne @PrimaryKeyJoinColumn private UserData userData; }

public class UserData implements Serializable

{ @Id private Long id; @OneToOne @PrimaryKeyJoinColumn private User user; }

This will result in this Exception:
org.eclipse.core.runtime.CoreException: org.hibernate.tool.hbm2x.ExporterException: Error while processing template view/list.xhtml.ftl
org.eclipse.core.runtime.CoreException[666]: org.hibernate.tool.hbm2x.ExporterException: Error while processing template view/list.xhtml.ftl
Caused by: freemarker.core.InvalidReferenceException: Expression property.value.typeName is undefined on line 39, column 6 in view/list.xhtml.ftl