0x800a1391 - JavaScript runtime error: 'DayPilot' is undefined

You tutorials and install documentation are incomplete because they leave out many of the details like using directives. I have no doubt you've left out something critical that is causing the error above.

My view has:

@Html.DayPilotGantt("Mission", new DayPilotGanttConfig
{
BackendURL = Url.Action("Backend", "Mission")
}

The controller is boilerplate from the tutorial--with the missing Using directives lifted out of the downloaded tutorial (for both the view and the controller).

Line 41 is where the error occurs, and it has:

var v=new DayPilot.Gantt('Mission');

I saw a similar bug report from years past and the response was completely inadequate for something this expensive. I expect more details than that.