Most likely, your paths are incorrect. This:
bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(
"~/jquery.unobtrusive.ajax*",
"~/jquery.validate.unobtrusive.bootstrap*"));
should be
bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(
"~/scripts/jquery.unobtrusive.ajax*",
"~/scripts/jquery.validate.unobtrusive.bootstrap*"));
Remember, ~/
maps to the site's virtual root directory when the path is being resolved, so unless you're placing JavaScript files in the site root, those paths in your bundle will not work.