not required field validating as required in mvc code example

Example: mvc 5 required field validation not working

//1. Get JQuery validation scripts via NuGet
//PM> install-package Microsot.JQuery.Unobtrusive.Validation
//2. Add .js reference to master page (_Layout.cshtml)
<script src="/Scripts/jquery.validate.js"></script>
<script src="/Scripts/jquery.validate.unobtrusive.js"></script>