// models without a version starting with 3.4.
            validateStringNotEmpty("modelVersion", problems, Severity.ERROR, Version.V20, m.getModelVersion(), m);

            validateModelVersion(problems, m.getModelVersion(), m, "4.0.0");

            validateStringNoExpression("groupId", problems, Severity.WARNING, Version.V20, m.getGroupId(), m);
            if (parent == null) {