If you are creating the navigator using @Html.DayPilotNavigator config helper in MVC then you are using the Pro version. The server-side Navigator bindings (including the config Html helper) are not included in the MVC Lite version.
You can create the navigator using the direct JavaScript API because it's included in the JavaScript library in the Lite version:
<div id="dp"></div>
<script type="text/javascript">
var dp = new DayPilot.Navigator("dp");
// ...
dp.init();
</script>